4 * INTERNATIONAL

Designation: E 92 - 82 (Reapproved 2003)*52

Standard Test Method for Vickers Hardness of Metallic Materials 1

T h i s s t a n d a r d i s i s s u e d u n d e r t h e fixed d e s i g n a t i o n E 9 2 ; t h e n u m b e r i m m e d i a t e l y f o l l o w i n g t h e d e s i g n a t i o n i n d i c a t e s t h e y e a r o f o r i g i n a l a d o p t i o n o r , i n t h e case o f r e v i s i o n , t h e y e a r o f l a s t r e v i s i o n . A n u m b e r i n p a r e n t h e s e s i n d i c a t e s t h e y e a r o f l a s t r e a p p r o v a l . A s u p e r s c r i p t e p s i l o n (e) i n d i c a t e s a n e d i t o r i a l c h a n g e s i n c e t h e l a s t r e v i s i o n o r r e a p p r o v a l .

This standard has been approved for use by agencies of the Department ofDefense.

e 1 N O T E — S e c t i o n 3 . 2 w a s e d i t o r i a l l y u p d a t e d i n J u n e 2 0 0 3 . e 2 N O T E — T a b l e 3 w a s e d i t o r i a l l y c o r r e c t e d i n J u n e 2 0 0 4 .

1. Scope 1.1 T h i s t e s t m e t h o d c o v e r s t h e d e t e r m i n a t i o n o f t h e V i c k e r s

h a r d n e s s o f m e t a l l i c m a t e r i a l s , u s i n g a p p l i e d f o r c e s o f 1 k g f t o 1 2 0 k g f , 2 t h e v e r i f i c a t i o n o f V i c k e r s h a r d n e s s t e s t i n g m a c h i n e s ( P a r t B ) , a n d t h e c a l i b r a t i o n o f s t a n d a r d i z e d h a r d n e s s t e s t b l o c k s ( P a r t C ) . T w o g e n e r a l c l a s s e s o f s t a n d a r d t e s t s a r e r e c o g n i z e d :

1 . 1 . 1 Verification, Laboratory, or Referee Tests, w h e r e a h i g h d e g r e e o f a c c u r a c y i s r e q u i r e d .

1 .1 .2 Routine Tests, w h e r e a s o m e w h a t l o w e r d e g r e e o f a c c u r a c y i s p e r m i s s i b l e .

1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.

2. Referenced Documents 2 . 1 ASTM Standards: E 4 P r a c t i c e s f o r F o r c e V e r i f i c a t i o n o f T e s t i n g M a c h i n e s 3

E 1 4 0 H a r d n e s s C o n v e r s i o n T a b l e s f o r M e t a l s ( R e l a t i o n s h i p A m o n g B r i n e l l H a r d n e s s , V i c k e r s H a r d n e s s , R o c k w e l l H a r d n e s s , R o c k w e l l S u p e r f i c i a l H a r d n e s s , K n o o p H a r d -n e s s , a n d S c l e r o s c o p e H a r d n e s s ) 3

1 T h i s t e s t m e t h o d i s u n d e r t h e j u r i s d i c t i o n o f A S T M C o m m i t t e e E 2 8 o n M e c h a n i c a l T e s t i n g a n d i s t h e d i r e c t r e s p o n s i b i l i t y o f S u b c o m m i t t e e E 2 8 . 0 6 o n I n d e n t a t i o n H a r d n e s s T e s t i n g .

C u r r e n t e d i t i o n a p p r o v e d J a n . 1 0 , 2 0 0 3 . P u b l i s h e d A p r i l 2 0 0 3 . O r i g i n a l l y a p p r o v e d i n 1 9 5 2 . L a s t p r e v i o u s e d i t i o n a p p r o v e d i n 1 9 9 7 as E 9 2 - 8 2 ( 1 9 9 7 ) e 3 .

2 A p r o c e d u r e c o v e r i n g V i c k e r s t e s t s u s i n g a p p l i e d f o r c e s o f 1 g f t o 1 0 0 0 g f ( 1 k g f ) m a y b e f o u n d i n T e s t M e t h o d E 3 8 4 , T e s t M e t h o d f o r M i c r o i n d e n t a t i o n H a r d n e s s o f M a t e r i a l s , a p p e a r i n g i n t h e Annual Book of ASTM Standards, V o l 0 3 . 0 1 .

3 Annual Book of ASTM Standards, V o l 0 3 . 0 1 .

E 3 8 4 T e s t M e t h o d f o r M i c r o i n d e n t a t i o n H a r d n e s s o f M a -t e r i a l s 3

3. Terminology 3 . 1 calibration—determination o f t h e v a l u e s o f t h e s i g n i f i -

c a n t p a r a m e t e r s b y c o m p a r i s o n w i t h v a l u e s i n d i c a t e d b y a r e f e r e n c e i n s t r u m e n t o r b y a s e t o f r e f e r e n c e s t a n d a r d s .

3 . 2 verification—confirmation b y e x a m i n a t i o n a n d p r o v i ¬s i o n o f e v i d e n c e t h a t a n i n s t r u m e n t , m a t e r i a l , r e f e r e n c e , o r s t a n d a r d i s i n c o n f o r m a n c e w i t h a s p e c i f i c a t i o n .

3 .3 Vickers hardness number, HV—a n u m b e r r e l a t e d t o t h e a p p l i e d f o r c e a n d t h e s u r f a c e a r e a o f t h e p e r m a n e n t i m p r e s s i o n m a d e b y a s q u a r e - b a s e d p y r a m i d a l d i a m o n d i n d e n t e r h a v i n g i n c l u d e d f a c e a n g l e s o f 136° ( see F i g . 1 a n d T a b l e 1 ) , c o m p u t e d f r o m t h e e q u a t i o n :

H V = 2Psin ( a / 2 ) / d 2 = 1 . 8 5 4 4 P / d 2 (1 )

w h e r e : P = f o r c e , k g f , d = m e a n d i a g o n a l o f i m p r e s s i o n , m m , a n d a = f a c e a n g l e o f d i a m o n d = 136°.

3 . 4 Vickers hardness test—an i n d e n t a t i o n h a r d n e s s t e s t u s i n g c a l i b r a t e d m a c h i n e s t o f o r c e a s q u a r e - b a s e d p y r a m i d a l d i a m o n d i n d e n t e r h a v i n g s p e c i f i e d f a c e a n g l e s , u n d e r a p r e d e -t e r m i n e d f o r c e , i n t o t h e s u r f a c e o f t h e m a t e r i a l u n d e r t e s t a n d t o m e a s u r e t h e d i a g o n a l s o f t h e r e s u l t i n g i m p r e s s i o n a f t e r r e m o v a l o f t h e f o r c e .

3 . 4 . 1 V i c k e r s h a r d n e s s t e s t s a r e m a d e a t t e s t f o r c e s o f 1 k g f t o 1 2 0 k g f .

3 . 4 . 2 F o r p r a c t i c a l p u r p o s e s t h e V i c k e r s h a r d n e s s n u m b e r i s c o n s t a n t w h e n a s q u a r e - b a s e d d i a m o n d p y r a m i d w i t h a f a c e a n g l e o f 136° i s u s e d w i t h a p p l i e d f o r c e s o f 5 k g f a n d h i g h e r .

Copyright © A S T M International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.

1

F I G . 1 V i c k e r s H a r d n e s s T e s t ( s e e T a b l e 1)

T A B L E 1 S y m b o l s a n d D e s i g n a t i o n s A s s o c i a t e d w i t h F i g . 1

Number Symbol Designation

1 Angle at the vertex of the pyramidal in­denter (136°)

2 P Test force in kilograms-force 3 d Arithmetic mean of the two diagonals d 1

and d2

T A B L E 2 V i c k e r s H a r d n e s s N u m b e r s ( D i a m o n d , 136° F a c e A n g l e , f o r c e o f 1 kgf)

Diagonal of Vickers Hardness Number for Diagonal Measured to 0.0001 mm Impression,

mm 0.0000 0.0001 0.0002 0.0003 0.0004 0.0005 0.0006 0.0007 0.0008 0.0009

0.005 74 170 71 290 68 580 66 020 63 590 61 300 59 130 57 080 55 120 53 270 0.006 51 510 49 840 48 240 46 720 45 270 43 890 42 570 41 310 40 100 38 950 0.007 37 840 36 790 35 770 34 800 33 860 32 970 32 100 31 280 30 480 29 710 0.008 28 970 28 260 27 580 26 920 26 280 25 670 25 070 24 500 23 950 23 410 0.009 22 890 22 390 21 910 21 440 20 990 20 550 20 120 19 710 19 310 18 920

0.010 18 540 18 180 17 820 17 480 17 140 16 820 16 500 16 200 15 900 15 610 0.011 15 330 15 050 14 780 14 520 14 270 14 020 13 780 13 550 13 320 13 090 0.012 12 880 12 670 12 460 12 260 12 060 11 870 11 680 11 500 11 320 11 140 0.013 10 970 10 810 10 640 10 480 10 330 10 170 10 030 9 880 9 737 9 598 0.014 9 461 9 327 9 196 9 068 8 943 8 820 8 699 8 581 8 466 8 353

0.015 8 242 8 133 8 026 7 922 7 819 7 718 7 620 7 523 7 428 7 335 0.016 7 244 7 154 7 066 6 979 6 895 6 811 6 729 6 649 6 570 6 493 0.017 6 416 6 342 6 268 6 196 6 1 2 5 6 055 5 986 5 919 5 853 5 787 0.018 5 723 5 660 5 598 5 537 5 477 5 418 5 360 5 303 5 247 5 191 0.019 5 137 5 083 5 030 4 978 4 927 4 877 4 827 4 778 4 730 4 683

0.020 4 636 4 590 4 545 4 500 4 456 4 413 4 370 4 328 4 286 4 245 0.021 4 205 4 165 4 126 4 087 4 049 4 012 3 975 3 938 3 902 3 866 0.022 3 831 3 797 3 763 3 729 3 696 3 663 3 631 3 599 3 567 3 536 0.023 3 505 3 475 3 445 3 416 3 387 3 358 3 329 3 301 3 274 3 246 0.024 3 219 3 193 3 166 3 140 3 115 3 089 3 064 3 039 3 015 2 991

0.025 2 967 2 943 2 920 2 897 2 874 2 852 2 830 2 808 2 786 2 764 0.026 2 743 2 722 2 701 2 681 2 661 2 641 2 621 2 601 2 582 2 563 0.027 2 544 2 525 2 506 2 488 2 470 2 452 2 434 2 417 2 399 2 382 0.028 2 365 2 348 2 332 2 315 2 299 2 283 2 267 2 251 2 236 2 220 0.029 2 205 2 190 2 175 2 160 2 145 2 131 2 116 2 102 2 088 2 074

0.030 2 060 2 047 2 033 2 020 2 007 1 993 1 980 1 968 1 955 1 942 0.031 1 930 1 917 1 905 1 893 1 881 1 869 1 857 1 845 1 834 1 822 0.032 1 811 1 800 1 788 1 777 1 766 1 756 1 745 1 734 1 724 1 713 0.033 1 703 1 693 1 682 1 672 1 662 1 652 1 643 1 633 1 623 1 614

2

E 92 - 82 (2003) e 2

T A B L E 2 Continued

Diagonal of Vickers Hardness Number for Diagonal Measured to 0.0001 mm

Mi ip i e s s i o i i , mm

0.0000 0.0001 0.0002 0.0003 0.0004 0.0005 0.0006 0.0007 0.0008 0.0009

0.034 1 604 1 595 1 585 1 576 1 567 1 558 1 549 1 540 1 531 1 522

0.035 1 514 1 505 1 497 1 488 1 480 1 471 1 463 1 455 1 447 1 439 0.036 1 431 1 423 1 415 1 407 1 400 1 392 1 384 1 377 1 369 1 362 0.037 1 355 1 347 1 340 1 333 1 326 1 319 1 312 1 305 1 298 1 291 0.038 1 284 1 277 1 271 1 264 1 258 1 251 1 245 1 238 1 232 1 225 0.039 1 219 1 213 1 207 1 201 1 195 1 189 1 183 1 177 1 171 1 165

0.040 1 159 1 153 1 147 1 142 1 136 1 131 1 125 1 119 1 114 1 109 0.041 1 103 1 098 1 092 1 087 1 082 1 077 1 072 1 066 1 061 1 056 0.042 1 051 1 046 1 041 1 036 1 031 1 027 1 022 1 017 1 012 1 008 0.043 1 003 998 994 989 985 980 975 971 967 962 0.044 958 953 949 945 941 936 932 928 924 920

0.045 916 912 908 904 900 896 892 888 884 880 0.046 876 873 869 865 861 858 854 850 847 843 0.047 839 836 832 829 825 822 818 815 812 808 0.048 805 802 798 795 792 788 785 782 779 775 0.049 772 769 766 763 760 757 754 751 748 745

0.050 742 739 736 733 730 727 724 721 719 716 0.051 713 710 707 705 702 699 696 694 691 688 0.052 686 683 681 678 675 673 670 668 665 663 0.053 660 658 655 653 650 648 645 643 641 638 0.054 636 634 631 629 627 624 622 620 617 615

0.055 613 611 609 606 604 602 600 598 596 593 0.056 591 589 587 585 583 581 579 577 575 573 0.057 571 569 567 565 563 561 559 557 555 553 0.058 551 549 547 546 544 542 540 538 536 535 0.059 533 531 529 527 526 524 522 520 519 516.8

0.060 515.1 513.4 511.7 510.0 508.3 506.6 505.0 503.3 501.6 500.0 0.061 498.4 496.7 495.1 493.5 491.9 490.3 488.7 487.1 485.5 484.0 0.062 482.4 480.9 479.3 477.8 476.2 474.7 473.2 471.7 470.2 468.7 0.063 467.2 465.7 464.3 462.8 461.3 459.9 458.4 457.0 455.6 454.1 0.064 452.7 451.3 449.9 448.5 447.1 445.7 444.4 443.0 441.6 440.3

0.065 438.9 437.6 436.2 434.9 433.6 432.2 430.9 429.6 428.3 427.0 0.066 425.7 424.4 423.1 421.9 420.6 419.3 418.1 416.8 415.6 414.3 0.067 413.1 411.9 410.6 409.4 408.2 407.0 405.8 404.6 403.4 402.2 0.068 401.0 399.9 398.7 397.5 396.6 395.2 394.0 392.9 391.8 390.6 0.069 389.5 388.4 387.2 386.1 385.0 383.9 382.8 381.7 380.6 379.5

0.070 378.4 377.4 376.3 375.2 374.2 373.1 372.0 371.0 369.9 368.9 0.071 367.9 366.8 365.8 364.8 363.7 362.7 361.7 360.7 359.7 358.7 0.072 357.7 356.7 355.7 354.7 353.8 352.8 351.8 350.9 349.9 348.9 0.073 348.0 347.0 346.1 345.1 344.2 343.3 342.3 341.4 340.5 339.6 0.074 338.6 337.7 336.8 335.9 335.0 334.1 333.2 332.3 331.4 330.5

0.075 329.7 328.8 327.9 327.0 326.2 325.3 324.5 323.6 322.7 321.9 0.076 321.0 320.2 319.4 318.5 317.7 316.9 316.0 315.2 314.4 313.6 0.077 312.8 312.0 311.1 310.3 309.5 308.7 307.9 307.2 306.4 305.6 0.078 304.8 304.0 303.2 302.5 301.7 300.9 300.2 299.4 298.6 297.9 0.079 297.1 296.4 295.6 294.9 294.1 293.4 292.7 291.9 291.2 290.5

0.080 289.7 289.0 288.3 287.6 286.9 286.2 285.4 284.7 284.0 283.3 0.081 282.6 281.9 281.2 280.6 279.9 279.2 278.5 277.8 277.1 276.5 0.082 275.8 275.1 274.4 273.8 273.1 272.4 271.8 271.1 270.5 269.8 0.083 269.2 268.5 267.9 267.2 266.6 266.0 265.3 264.7 264.1 263.4 0.084 262.8 262.2 261.6 260.9 260.3 259.7 259.1 258.5 257.9 257.3

0.085 256.7 256.1 255.5 254.9 254.3 253.7 253.1 252.5 251.9 251.3 0.086 250.7 250.1 249.6 249.0 248.4 247.8 247.3 246.7 246.1 245.6 0.087 245.0 244.4 243.9 243.3 242.8 242.2 241.6 241.1 240.6 240.0 0.088 239.5 238.9 238.4 237.8 237.3 236.8 236.2 235.7 235.2 234.6 0.089 234.1 233.6 233.1 232.5 232.0 231.5 231.0 230.5 230.0 229.4

0.090 228.9 228.4 227.9 227.4 226.9 226.4 225.9 225.4 224.9 224.4 0.091 223.9 223.4 222.9 222.5 222.0 221.5 221.0 220.5 220.0 219.6 0.092 219.1 218.6 218.1 217.7 217.1 216.7 216.3 215.8 215.3 214.9 0.093 214.4 213.9 213.5 213.0 212.6 212.1 211.7 211.2 210.8 210.3

3

E 92 - 82 (2003) e 2

T A B L E 2 Continued

D i a g o n a l o f Vickers Hardness Number for Diagonal Measured to 0.0001 mm Impression,

mm 0.0000 0.0001 0.0002 0.0003 0.0004 0.0005 0.0006 0.0007 0.0008 0.0009

0.094 209.9 209.4 209.0 208.5 208.1 207.6 207.2 206.8 206.3 205.9

0.095 205.5 205.0 204.6 204.2 203.8 203.3 202.9 202.5 202.1 201.6 0.096 201.2 200.8 200.4 200.0 199.5 199.1 198.7 198.3 197.9 197.5 0.097 197.1 196.7 196.3 195.9 195.5 195.1 194.7 194.3 193.9 193.5 0.098 193.1 192.7 192.3 191.9 191.5 191.1 190.7 190.4 190.0 189.6 0.099 189.2 188.8 188.4 188.1 187.7 187.3 186.9 186.6 186.2 185.5

A t l o w e r t e s t f o r c e s t h e V i c k e r s h a r d n e s s m a y b e f o r c e -d e p e n d e n t . I n T a b l e 2 a r e g i v e n t h e V i c k e r s h a r d n e s s n u m b e r s f o r a t e s t f o r c e o f 1 k g f . F o r o b t a i n i n g h a r d n e s s n u m b e r s w h e n o t h e r t e s t f o r c e s a r e u s e d , t h e V i c k e r s h a r d n e s s n u m b e r o b t a i n e d f r o m T a b l e 2 i s m u l t i p l i e d b y t h e t e s t f o r c e i n k i l o g r a m s - f o r c e ( T a b l e 3 ) .

N O T E 1 — T h e V i c k e r s h a r d n e s s n u m b e r i s f o l l o w e d b y t h e s y m b o l H V

T A B L E 3 D e c i m a l P o i n t F i n d e r f o r U s e w i t h T a b l e 2 A n e x a m p l e o f d e t e r m i n a t i o n of h a r d n e s s n u m b e r s f o l l o w s t he tab le .

Diagonal Length, mm

Vickers Hardness 1-kgf Force

0.005 74 200 0.006 51 500 0.007 37 800 0.008 29 000 0.009 22 900 0.010 18 540 0.020 4 640 0.030 2 060 0.040 1 159 0.050 742 0.060 515 0.070 378 0.080 290 0.090 229 0.100 185.4 0.200 46.4 0.300 20.6 0.400 11.6 0.500 7.42 0.600 5.15 0.700 3.78 0.800 2.90 0.900 2.29 1.000 1.85 1.100 1.53 1.200 1.29 1.300 1.10 1.400 0.946 1.500 0.824 1.600 0.724 1.700 0.642 1.800 0.572 1.900 0.514 2.000 0.464

Example—Using a 50-kgf test force, the average measured diagonal length = 0.644 mm. In Table 2 read:

HV = 447 at 0.0644-mm diagonal length at 1-kgf force.

Using Table 3 determine:

HV = 4.47 at 0.644-mm diagonal length at 1-kgf force.

50 X 4.47 = 224 HV for 50-kg test force.

w i t h a s u f f i x n u m b e r d e n o t i n g t h e f o r c e a n d s e c o n d s u f f i x n u m b e r i n d i c a t i n g t h e d u r a t i o n o f f o r c e i n g w h e n t h e l a t t e r d i f f e r s f r o m 1 0 t o 1 5 s, w h i c h i s t h e n o r m a l f o r c e t i m e . Example: 4 4 0 H V 3 0 = V i c k e r s h a r d n e s s o f 4 4 0 m e a s u r e d u n d e r a f o r c e o f 3 0 k g f

a p p l i e d f o r 10 t o 15 s. 4 4 0 H V 3 0 / 2 0 = V i c k e r s h a r d n e s s o f 4 4 0 m e a s u r e d u n d e r a f o r c e o f 3 0

k g f a p p l i e d f o r 2 0 s.

A. G E N E R A L DESCRIPTION AND T E S T P R O C E D U R E F O R V I C K E R S HARDNESS T E S T S

4. Apparatus 4 . 1 Testing Machine—Equipment f o r V i c k e r s h a r d n e s s t e s t -

i n g u s u a l l y c o n s i s t s o f a t e s t i n g m a c h i n e w h i c h s u p p o r t s t h e s p e c i m e n a n d p e r m i t s t h e i n d e n t e r a n d t h e s p e c i m e n t o b e b r o u g h t i n t o c o n t a c t g r a d u a l l y a n d s m o o t h l y u n d e r a p r e d e t e r -m i n e d f o r c e , w h i c h i s a p p l i e d f o r a fixed p e r i o d o f t i m e . T h e d e s i g n o f t h e m a c h i n e s h o u l d b e s u c h t h a t n o r o c k i n g o r l a t e r a l m o v e m e n t o f t h e i n d e n t e r o r s p e c i m e n i s p e r m i t t e d w h i l e t h e f o r c e i s b e i n g a p p l i e d o r r e m o v e d . A m e a s u r i n g m i c r o s c o p e i s u s u a l l y m o u n t e d o n t h e m a c h i n e i n s u c h a m a n n e r t h a t t h e i m p r e s s i o n i n t h e s p e c i m e n m a y b e r e a d i l y l o c a t e d i n t h e o p t i c a l field.

4 . 2 Indenter: 4 . 2 . 1 T h e i n d e n t e r s h a l l b e a h i g h l y p o l i s h e d , p o i n t e d ,

s q u a r e - b a s e d p y r a m i d a l d i a m o n d w i t h f a c e a n g l e s o f 136° 6 3 0 m i n .

4 . 2 . 2 A l l f o u r f a c e s o f t h e i n d e n t e r s h a l l b e e q u a l l y i n c l i n e d t o t h e a x i s o f t h e i n d e n t e r ( w i t h i n 6 3 0 m i n ) a n d m e e t a t a s h a r p p o i n t , t h a t i s , t h e l i n e o f j u n c t i o n b e t w e e n o p p o s i t e f a c e s s h a l l n o t b e m o r e t h a n 0 . 0 0 1 m m i n l e n g t h a s s h o w n i n F i g . 2 .

4 . 2 . 3 T h e d i a m o n d s h o u l d b e e x a m i n e d p e r i o d i c a l l y a n d i f i t i s l o o s e i n t h e m o u n t i n g m a t e r i a l , c h i p p e d , o r c r a c k e d , i t s h o u l d b e d i s c a r d e d o r r e c o n d i t i o n e d .

FIG. 2 J u n c t i o n o f I n d e n t e r F a c e s

4

E 92

N O T E 2 — T h e c o n d i t i o n o f t h e p o i n t o f t h e i n d e n t e r i s o f c o n s i d e r a b l e i m p o r t a n c e w h e r e t h e t e s t f o r c e i s l i g h t a n d t h e i m p r e s s i o n i s s m a l l . I t i s r e c o m m e n d e d t h a t t h e p o i n t be p e r i o d i c a l l y c h e c k e d b y e x a m i n i n g a n i m p r e s s i o n m a d e i n a p o l i s h e d s t e e l b l o c k . U n d e r a m a g n i f i c a t i o n o f 6 0 0 X o r m o r e , u s i n g a v e r t i c a l i l l u m i n a t o r , a n y c h i p p i n g o r r o u n d i n g o f t h e p o i n t c a n b e d e t e c t e d a n d t h e e x t e n t o f t h e d e f e c t m e a s u r e d w i t h a filar m i c r o m e t e r . I t i s r e c o m m e n d e d t h a t a d i a m o n d p y r a m i d i n d e n t e r s h o u l d n o t b e u s e d f o r t e s t s i n w h i c h t h e m a x i m u m l e n g t h o f s u c h a d e f e c t e x c e e d s 5 % o f t h e l e n g t h o f t h e i m p r e s s i o n d i a g o n a l .

4 . 3 Measuring Microscope—The d i v i s i o n s o f t h e m i c r o m e -t e r s c a l e o f t h e m e a s u r i n g m i c r o s c o p e o r o t h e r m e a s u r i n g d e v i c e s h a l l b e s o c o n s t r u c t e d t h a t t h e l e n g t h o f t h e d i a g o n a l s o f a n i m p r e s s i o n i n a p r o p e r l y s u r f a c e - f i n i s h e d s p e c i m e n ( see s e c t i o n 5 . 1 . 2 ) c a n b e m e a s u r e d t o w i t h i n 6 0 . 0 0 0 5 m m o r 6 0 . 5 %, w h i c h e v e r i s l a r g e r .

5. Test Specimen 5 . 1 T h e V i c k e r s h a r d n e s s t e s t i s a d a p t a b l e t o a w i d e v a r i e t y

o f t e s t s p e c i m e n s r a n g i n g f r o m l a r g e b a r s a n d r o l l e d s e c t i o n s t o m i n u t e p i e c e s i n m e t a l l o g r a p h i c m o u n t s . I n g e n e r a l t h e b a c k s o f t h e s p e c i m e n s s h a l l b e s o finished o r t h e s p e c i m e n s s h a l l b e s o c l a m p e d t h a t t h e r e i s n o p o s s i b i l i t y o f t h e i r r o c k i n g o r s h i f t i n g u n d e r t h e t e s t f o r c e . T h e s p e c i m e n s s h a l l a l s o c o n f o r m t o t h e r e q u i r e m e n t s g i v e n i n t h e f o l l o w i n g 5 . 1 . 1 , 5 . 1 . 2 , a n d 5 . 1 . 3 .

5 . 1 . 1 Thickness—The t h i c k n e s s o f t h e t e s t s p e c i m e n s h a l l b e s u c h t h a t n o b u l g e o r m a r k i n g s h o w i n g t h e e f f e c t o f t h e f o r c e a p p e a r s o n t h e s i d e o f t h e s p e c i m e n o p p o s i t e t h e i m p r e s s i o n . I n a n y e v e n t t h e t h i c k n e s s o f t h e s p e c i m e n s h a l l b e a t l e a s t o n e a n d o n e h a l f t i m e s t h e l e n g t h o f t h e d i a g o n a l . W h e n l a m i n a t e d m a t e r i a l i s t e s t e d , t h e t h i c k n e s s o f t h e i n d i v i d u a l c o m p o n e n t b e i n g t e s t e d s h a l l b e u s e d f o r t h e t h i c k n e s s -d i a g o n a l l e n g t h r e l a t i o n s h i p .

5 . 1 . 2 Finish—The s u r f a c e o f t h e s p e c i m e n s h o u l d b e s o p r e p a r e d t h a t t h e e n d s o f t h e d i a g o n a l s a r e c l e a r l y d e f i n e d a n d c a n b e r e a d w i t h p r e c i s i o n o f 6 0 . 0 0 0 5 m m o r 6 0 . 5 % o f t h e l e n g t h o f t h e d i a g o n a l s , w h i c h e v e r i s l a r g e r . C a r e s h o u l d b e t a k e n i n s p e c i m e n p r e p a r a t i o n t o a v o i d t e m p e r i n g d u r i n g g r i n d i n g , o r w o r k - h a r d e n i n g t h e s u r f a c e d u r i n g p o l i s h i n g .

5 . 1 . 3 Alignment—The s p e c i m e n s h o u l d b e s o p r e p a r e d o r m o u n t e d t h a t t h e s u r f a c e i s n o r m a l t o t h e a x i s o f t h e i n d e n t e r w i t h i n 6 1° o f a n g l e . T h i s c a n r e a d i l y b e a c c o m p l i s h e d b y s u r f a c e g r i n d i n g ( o r o t h e r w i s e m a c h i n i n g ) t h e o p p o s i t e s i d e o f t h e s p e c i m e n t o p a r a l l e l i s m w i t h t h e s i d e t o b e t e s t e d .

5 . 1 . 4 Radius of Curvature—Until f u r t h e r i n v e s t i g a t i v e w o r k i s a c c o m p l i s h e d t o d e t e r m i n e t h e e f f e c t o f t h e r a d i u s o f c u r v a t u r e o n r e a d i n g s , d u e c a u t i o n s h o u l d b e u s e d i n i n t e r p r e t -i n g o r a c c e p t i n g t h e r e s u l t s o f t e s t s m a d e o n c y l i n d r i c a l s u r f a c e s .

N O T E 3 — A m e t h o d r e c o m m e n d e d b y t h e I n t e r n a t i o n a l O r g a n i z a t i o n f o r S t a n d a r d i z a t i o n f o r c o r r e c t i n g V i c k e r s h a r d n e s s r e a d i n g s t a k e n o n s p h e r i -c a l o r c y l i n d r i c a l s u r f a c e s i s g i v e n i n T a b l e 4 , T a b l e 5 , a n d T a b l e 6.

N O T E 4 — T h e s e t a b l e s g i v e c o r r e c t i o n f a c t o r s t o be a p p l i e d t o V i c k e r s h a r d n e s s v a l u e s o b t a i n e d w h e n t e s t s a r e m a d e o n s p h e r i c a l o r c y l i n d r i c a l s u r f a c e s . T h e c o r r e c t i o n f a c t o r s a r e t a b u l a t e d i n t e r m s o f t h e r a t i o o f t h e m e a n d i a g o n a l d o f t h e i n d e n t a t i o n t o t h e d i a m e t e r D o f t h e s p h e r e o r c y l i n d e r . E x a m p l e s o f t h e u s e o f t h e s e t a b l e s a r e :

82 (2003) e 2

T A B L E 4 C o r r e c t i o n F a c t o r s f o r U s e i n V i c k e r s H a r d n e s s T e s t s M a d e o n S p h e r i c a l S u r f a c e s

Convex Surface Concave Surface

d/DA Correction Factor d/DA Correction

Factor

0.004 0.009 0.013

0.995 0.990 0.985

0.004 0.008 0.012

1.005 1.010 1.015

0.018 0.023 0.028

0.980 0.975 0.970

0.016 0.020 0.024

1.020 1.025 1.030

0.033 0.038 0.043

0.965 0.960 0.955

0.028 0.031 0.035

1.035 1.040 1.045

0.049 0.055 0.061

0.950 0.945 0.940

0.038 0.041 0.045

1.050 1.055 1.060

0.067 0.073 0.079

0.935 0.930 0.925

0.048 0.051 0.054

1.065 1.070 1.075

0.086 0.093 0.100

0.920 0.915 0.910

0.057 0.060 0.063

1.080 1.085 1.090

0.107 0.114 0.122

0.905 0.900 0.895

0.066 0.069 0.071

1.095 1.100 1.105

0.130 0.139 0.147

0.890 0.885 0.880

0.074 0.077 0.079

1.110 1.115 1.200

0.156 0.165 0.175

0.875 0.870 0.865

0.082 0.084 0.087

1.125 1.130 1.135

0.185 0.195 0.206

0.860 0.855 0.850

0.089 0.091 0.094

1.140 1.145 1.150

AD= diameter of sphere. d= mean diagonal of impression in millimeters.

Example 1. Convex Sphere: Diameter of sphere, D Load Mean diagonal of impression, d

d/D = 0.150/10 = 0.015 From Tables 2 and 3, HV From Table 4, by interpolation,

correction factor Hardness of sphere = 824 X 0.983

Example 2. Concave Cylinder, One Diagonal Parallel to Axis: Diameter of cylinder, D = 5 mm Load = 30 kgf Mean diagonal of impression, d = 0.415 mm

d/D = 0.415/5 = 0.083 From Tables 2 and 3, HV = 323 From Table 6, correction factor = 1.075 Hardness of cylinder = 323 X 1.075 = 347 HV 30.

= 1 0 m m = 10 kgf = 0.150 mm

= 824

= 0.983 = 810 HV 10

6. Verification of Apparatus 6 . 1 T h e h a r d n e s s t e s t i n g m a c h i n e s h a l l b e v e r i f i e d a s s p e c i -

fied i n P a r t B . 6 . 1 . 1 T w o a c c e p t a b l e m e t h o d s o f v e r i f y i n g V i c k e r s h a r d n e s s

t e s t i n g m a c h i n e s a r e g i v e n i n P a r t B .

5

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T A B L E 5 C o r r e c t i o n F a c t o r s f o r U s e i n V i c k e r s H a r d n e s s T e s t s M a d e o n C y l i n d r i c a l S u r f a c e s

(D iagona l s at 45° to t he ax is)

Convex Surface Concave Surface

d/DA Correction Factor d/DA Correction Factor

0.009 0.995 0.009 1.005 0.017 0.990 0.017 1.020 0.026 0.985 0.025 1.015

0.035 0.980 0.034 1.020 0.044 0.975 0.042 1.025 0.053 0.970 0.050 1.030

0.062 0.965 0.058 1.035 0.071 0.960 0.066 1.040 0.081 0.955 0.074 1.045

0.090 0.950 0.082 1.050 0.100 0.945 0.089 1.055 0.109 0.940 0.097 1.060

0.119 0.935 0.104 1.065 0.129 0.930 0.112 1.070 0.139 0.925 0.119 1.075

0.149 0.920 0.127 1.080 0.159 0.915 0.134 1.085 0.169 0.910 0.141 1.090

0.179 0.905 0.148 1.095 0.189 0.900 0.155 1.100 0.200 0.895 0.162 1.105

0.169 1.110 0.176 1.115 0.183 1.120

0.189 1.125 0.196 1.130 0.203 1.135

0.209 1.140 0.216 1.140 0.222 1.150

AD = diameter of cylinder. d = mean diagonal of impression in millimeters.

7. Procedure

7 . 1 Magnitude of Test Force—Test f o r c e s o f 1 k g f t o 1 2 0 k g f m a y b e u s e d , d e p e n d i n g o n t h e r e q u i r e m e n t s o f t h e t e s t . A l t h o u g h t e s t s o n h o m o g e n e o u s m a t e r i a l s i n d i c a t e t h a t t h e V i c k e r s h a r d n e s s n u m b e r i s n e a r l y i n d e p e n d e n t o f t h e t e s t f o r c e , t h i s c o n d i t i o n w i l l n o t b e p r e s e n t i n c a s e s w h e r e t h e r e i s a h a r d n e s s g r a d i e n t f r o m t h e s p e c i m e n s u r f a c e t o t h e i n t e r i o r o f t h e s p e c i m e n . T h e m a g n i t u d e o f t h e t e s t f o r c e s h o u l d t h e r e f o r e b e s t a t e d i n t h e t e s t r e p o r t ( S e c t i o n 1 1 ) .

7 . 2 Application of Test Force—Apply t h e t e s t f o r c e a n d r e l e a s e s m o o t h l y w i t h o u t s h o c k o r v i b r a t i o n . T h e t i m e o f a p p l i c a t i o n o f t h e f u l l t e s t f o r c e s h a l l b e 1 0 t o 15 s, u n l e s s o t h e r w i s e s p e c i f i e d .

7 . 3 Spacing ofIndentations—The c e n t e r o f t h e i m p r e s s i o n s h a l l n o t b e c l o s e r t o a n y e d g e o f t h e t e s t s p e c i m e n o r t o a n o t h e r i m p r e s s i o n t h a n a d i s t a n c e e q u a l t o t w o a n d o n e h a l f t i m e s t h e l e n g t h o f d i a g o n a l o f t h e i m p r e s s i o n . W h e n l a m i n a t e d m a t e r i a l i s t e s t e d , a b o n d s u r f a c e s h a l l b e c o n s i d e r e d a s a n e d g e f o r s p a c i n g o f i n d e n t a t i o n c a l c u l a t i o n s .

82 (2003) e 2

T A B L E 6 C o r r e c t i o n F a c t o r s f o r U s e i n V i c k e r s H a r d n e s s T e s t s M a d e o n C y l i n d r i c a l S u r f a c e s

(One d i a g o n a l para l le l to ax is)

Convex Surface Concave Surface

d/DA Correction Factor d/DA Correction Factor

0.009 0.995 0.048 1.035 0.019 0.990 0.053 1.040 0.029 0.985 0.058 1.045 0.041 0.980 0.063 1.050 0.054 0.975 0.067 1.055 0.068 0.970 0.071 1.060 0.085 0.965 0.076 1.065 0.104 0.960 0.079 1.070 0.126 0.955 0.083 1.075 0.153 0.950 0.087 1.080 0.189 0.945 0.090 1.085 0.243 0.940 0.093

0.097

1.090

1.095 Concave Surface 0.100 1.100

0.103 1.105

d/DA Correction Factor 0.105 0.108 0.111

1.110 1.115 1.120

0.008 1.005 0.113 1.125 0.016 1.020 0.116 1.130 0.023 1.015 0.118 1.135 0.030 1.020 0.120 1.140 0.036 1.025 0.123 1.145 0.042 1.030 0.125 1.150

AD = diameter of cylinder. d = mean diagonal of impression in millimeters.

8. Measurement of Impression 8 . 1 B o t h d i a g o n a l s o f t h e i m p r e s s i o n s h a l l b e m e a s u r e d a n d

t h e i r m e a n v a l u e u s e d as a b a s i s f o r c a l c u l a t i o n o f t h e V i c k e r s h a r d n e s s n u m b e r . I t i s r e c o m m e n d e d t h a t t h e m e a s u r e m e n t b e m a d e w i t h t h e i m p r e s s i o n c e n t e r e d a s n e a r l y a s p o s s i b l e i n t h e field o f t h e m i c r o s c o p e .

8 . 2 I n t h e c a s e o f a n i s o t r o p i c m a t e r i a l s , f o r e x a m p l e m a t e ¬r i a l s t h a t h a v e b e e n h e a v i l y c o l d w o r k e d , t h e r e m a y b e a d i f f e r e n c e b e t w e e n t h e l e n g t h s o f t h e t w o d i a g o n a l s o f t h e i m p r e s s i o n . I n s u c h c a s e s , t h e t e s t s p e c i m e n s h o u l d b e r e o r i -e n t e d s o t h a t t h e d i a g o n a l s o f a n e w i m p r e s s i o n a r e a p p r o x i -m a t e l y o f e q u a l l e n g t h .

9. Accuracy 9 . 1 T h e a c c u r a c y o f t h e V i c k e r s h a r d n e s s m e t h o d i s a

f u n c t i o n o f t h e a c c u r a c i e s o f t h e t e s t f o r c e , i n d e n t e r , a n d m e a s u r i n g d e v i c e . T h e c o n d i t i o n o f t h e t e s t a n d s u p p o r t s u r f a c e s a n d s u p p o r t o f t h e t e s t p i e c e d u r i n g a p p l i c a t i o n o f t h e t e s t f o r c e a l s o a f f e c t a c c u r a c y . U n d e r o p t i m u m c o n d i t i o n s o f t h e s e f a c t o r s t h e a c c u r a c y t h a t c a n b e e x p e c t e d i s t h e e q u i v a l e n t o f 4 % o f t h e V i c k e r s h a r d n e s s n u m b e r o f t h e s t a n d a r d i z e d r e f e r e n c e h a r d n e s s t e s t b l o c k s ( s e e s e c t i o n 1 8 . 2 ) . U n d e r l e s s t h a n i d e a l c o n d i t i o n s t h e r e d u c t i o n i n a c c u r a c y , w h e n r e q u i r e d , c a n b e e s t a b l i s h e d e m p i r i c a l l y b y e m p l o y i n g s t a t i s t i c a l m e t h -o d s .

10. Conversion to Other Hardness Scales or Tensile Strength Values

1 0 . 1 T h e r e i s n o g e n e r a l m e t h o d f o r c o n v e r t i n g a c c u r a t e l y V i c k e r s h a r d n e s s n u m b e r s t o o t h e r h a r d n e s s s c a l e s o r t e n s i l e s t r e n g t h v a l u e s . S u c h c o n v e r s i o n s a r e , a t b e s t , a p p r o x i m a t i o n s

I I

6

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a n d t h e r e f o r e s h o u l d b e a v o i d e d , e x c e p t f o r s p e c i a l c a s e s w h e r e a r e l i a b l e b a s i s f o r t h e a p p r o x i m a t e c o n v e r s i o n s h a s b e e n o b t a i n e d b y c o m p a r i s o n t e s t s .

N O T E 5 — S t a n d a r d E 1 4 0 g i v e s a p p r o x i m a t e c o n v e r s i o n v a l u e s f o r s p e c i f i c m a t e r i a l s s u c h as s t e e l , n i c k e l a n d h i g h - n i c k e l a l l o y s , a n d c a r t r i d g e b r a s s .

11. Report 1 1 . 1 T h e r e p o r t s h a l l i n c l u d e t h e f o l l o w i n g i n f o r m a t i o n : 1 1 . 1 . 1 T h e V i c k e r s h a r d n e s s n u m b e r , 1 1 . 1 . 2 T h e t e s t f o r c e u s e d ( s ee 3 . 4 . 2 , N o t e 1 ) , a n d 1 1 . 1 . 3 T h e f o r c e a p p l i c a t i o n t i m e , i f o t h e r t h a n 1 0 t o 1 5 s

(see 3 . 4 . 2 , N o t e 1 ) .

12. Precision and Bias 1 2 . 1 D u e t o t h e w i d e v a r i e t y o f m a t e r i a l s t e s t e d b y t h i s

m e t h o d a n d t h e p o s s i b l e v a r i a t i o n s i n t e s t s p e c i m e n s , t h e p r e c i s i o n o f t h i s m e t h o d h a s n o t b e e n e s t a b l i s h e d . T h e a c c e p t e d p r a c t i c e i s t o u t i l i z e t h e i n f o r m a t i o n i n 9 . 1 w h e n e s t a b l i s h i n g h a r d n e s s t o l e r a n c e s f o r s p e c i f i c a p p l i c a t i o n s . T h e p r e c i s i o n o f t h i s m e t h o d , w h e t h e r i n v o l v i n g a s i n g l e o p e r a t o r , m u l t i p l e o p e r a t o r s , o r m u l t i p l e l a b o r a t o r i e s , c a n b e e s t a b l i s h e d b y e m p l o y i n g s t a t i s t i c a l m e t h o d s .

B. V E R I F I C A T I O N O F V I C K E R S HARDNESS T E S T I N G MACHINES

13. Scope 1 3 . 1 P a r t B c o v e r s t w o p r o c e d u r e s f o r t h e v e r i f i c a t i o n o f

V i c k e r s h a r d n e s s t e s t i n g m a c h i n e s a n d a p r o c e d u r e t h a t i s r e c o m m e n d e d f o r u s e t o c o n f i r m t h a t t h e m a c h i n e h a s n o t b e c o m e m a l a d j u s t e d i n t h e i n t e r v a l s b e t w e e n t h e p e r i o d i c a l r o u t i n e c h e c k s . T h e t w o m e t h o d s o f v e r i f i c a t i o n a r e :

1 3 . 1 . 1 S e p a r a t e v e r i f i c a t i o n o f f o r c e a p p l i c a t i o n , i n d e n t e r , a n d m e a s u r i n g m i c r o s c o p e .

1 3 . 1 . 2 V e r t i f i c a t i o n b y s t a n d a r d i z e d t e s t b l o c k m e t h o d . 1 3 . 2 T h e first p r o c e d u r e ( 1 3 . 1 . 1 ) i s m a n d a t o r y f o r n e w a n d

r e b u i l t m a c h i n e s . 1 3 . 3 T h e s e c o n d p r o c e d u r e ( 1 3 . 1 . 2 ) s h a l l b e u s e d f o r v e r i -

f y i n g m a c h i n e s i n s e r v i c e .

14. General Requirements 1 4 . 1 B e f o r e a V i c k e r s h a r d n e s s t e s t i n g m a c h i n e i s v e r i f i e d

t h e m a c h i n e s h a l l b e e x a m i n e d t o e n s u r e t h a t : 1 4 . 1 . 1 T h e m a c h i n e i s p r o p e r l y s e t u p . 1 4 . 1 . 2 T h e i n d e n t e r h o l d e r i s m o u n t e d n o r m a l l y i n t h e

p l u n g e r . 1 4 . 1 . 3 T h e f o r c e c a n b e a p p l i e d a n d r e m o v e d w i t h o u t s h o c k

o r v i b r a t i o n i n s u c h a m a n n e r t h a t t h e r e a d i n g s a r e n o t i n f l u e n c e d .

1 4 . 2 I f t h e m e a s u r i n g d e v i c e i s i n t e g r a l w i t h t h e m a c h i n e , t h e m a c h i n e s h a l l b e e x a m i n e d t o e n s u r e t h a t :

1 4 . 2 . 1 T h e c h a n g e f r o m f o r c e i n g t o m e a s u r i n g d o e s n o t i n f l u e n c e t h e r e a d i n g s .

1 4 . 2 . 2 T h e m e t h o d o f i l l u m i n a t i o n d o e s n o t a f f e c t t h e r e a d i n g s .

1 4 . 2 . 3 T h e c e n t e r o f t h e i m p r e s s i o n i s i n t h e c e n t e r o f t h e field o f v i e w .

82 (2003) e 2

15. Verification 1 5 . 1 Separate Verification of Force Application, Indenter,

and Measuring Microscope: 1 5 . 1 . 1 force Application—The a p p l i e d f o r c e s h a l l b e

c h e c k e d b y t h e u s e o f d e a d w e i g h t s a n d p r o v i n g l e v e r s , o r b y a n e l a s t i c c a l i b r a t i o n d e v i c e o r s p r i n g s i n t h e m a n n e r d e s c r i b e d i n P r a c t i c e s E 4 . S u c h d e a d w e i g h t s o r o t h e r f o r c e i n g d e v i c e s s h a l l b e a c c u r a t e t o 6 0 . 2 %. V i c k e r s h a r d n e s s t e s t i n g m a c h i n e s s h a l l b e v e r i f i e d a t a m i n i m u m o f t h r e e a p p l i e d f o r c e s i n c l u d i n g t h e t e s t f o r c e s p e c i f i e d . A m i n i m u m o f t h r e e r e a d i n g s s h o u l d b e t a k e n a t e a c h f o r c e . A V i c k e r s h a r d n e s s t e s t i n g m a c h i n e i s a c c e p t a b l e f o r u s e o v e r a f o r c e i n g r a n g e w i t h i n w h i c h t h e m a c h i n e e r r o r d o e s n o t e x c e e d 6 1 % .

1 5 . 1 . 2 Indenter—The f o r m o f t h e d i a m o n d i n d e n t e r s h a l l b e v e r i f i e d b y d i r e c t m e a s u r e m e n t o f i t s s h a p e o r b y m e a s u r e -m e n t s o f i t s p r o j e c t i o n o n a s c r e e n . T h e a n g l e b e t w e e n o p p o s i t e f a c e s o f t h e p y r a m i d s h a l l b e 136° 6 3 0 m i n . A l l f o u r f a c e s s h a l l b e e q u a l l y i n c l i n e d t o t h e a x i s o f t h e p y r a m i d w i t h i n 6 3 0 m i n . T h e f o u r f a c e s o f i n d e n t e r s u s e d f o r l a b o r a t o r y , o r r o u t i n e t e s t s , s h a l l m e e t a t a p o i n t n o m o r e t h a n 0 . 0 0 1 m m i n l e n g t h (see F i g . 2 ) . T h e f o u r f a c e s o f i n d e n t e r s u s e d i n c a l i b r a t i n g s t a n d a r d i z e d h a r d n e s s t e s t b l o c k s , s h a l l m e e t a t a p o i n t i n w h i c h t h e l i n e o f j u n c t i o n b e t w e e n o p p o s i t e f a c e s i s n o m o r e t h a n 0 . 0 0 0 5 m m i n l e n g t h (see F i g . 3 ) . T h e q u a d r i l a t e r a l t h a t w o u l d b e f o r m e d b y t h e i n t e r s e c t i o n o f t h e f o u r f a c e s w i t h a p l a n e p e r p e n d i c u l a r t o t h e a x i s o f t h e i n d e n t e r s h a l l h a v e a n g l e s o f 90° 6 12 m i n .

1 5 . 1 . 3 Measuring Microscope—The m e a s u r i n g m i c r o s c o p e o r o t h e r d e v i c e f o r m e a s u r i n g t h e d i a g o n a l s o f t h e i m p r e s s i o n s h a l l b e c a l i b r a t e d a g a i n s t a n a c c u r a t e l y r u l e d l i n e s c a l e ( s t a g e m i c r o m e t e r ) . T h e e r r o r s o f t h e l i n e s c a l e s h a l l n o t e x c e e d 0 . 0 5 p m ( 0 . 0 0 0 0 5 m m ) o r 0 . 0 5 % o f a n y i n t e r v a l , w h i c h e v e r i s g r e a t e r . T h e m e a s u r i n g m i c r o s c o p e s h a l l b e c a l i b r a t e d t h r o u g h -o u t i t s r a n g e o f u s e a n d a c a l i b r a t i o n f a c t o r c h o s e n s u c h t h a t t h e e r r o r s h a l l n o t e x c e e d 6 0 . 5 %. I t m a y b e n e c e s s a r y t o d i v i d e t h e c o m p l e t e r a n g e o f t h e m i c r o m e t e r m i c r o s c o p e i n t o s e v e r a l s u b r a n g e s , e a c h h a v i n g i t s o w n f a c t o r .

1 5 . 2 Verification by Standardized Test Block Method: 1 5 . 2 . 1 A V i c k e r s h a r d n e s s t e s t i n g m a c h i n e u s e d o n l y f o r

r o u t i n e t e s t i n g m a y b e c h e c k e d b y m a k i n g a s e r i e s o f i m p r e s -s i o n s o n s t a n d a r d i z e d h a r d n e s s t e s t b l o c k s ( P a r t C ) .

1 5 . 2 . 2 A m i n i m u m o f five V i c k e r s h a r d n e s s r e a d i n g s s h a l l b e t a k e n o n a t l e a s t t h r e e b l o c k s h a v i n g d i f f e r e n t l e v e l s o f

F I G . 3 J u n c t i o n o f I n d e n t e r F a c e s

I I

7

- 82 (2003) e 2 E 92

h a r d n e s s u s i n g a t e s t f o r c e o r f o r c e s as s p e c i f i e d b y t h e u s e r w i t h t h e t e s t f o r c e a p p l i e d f o r 1 2 s.

1 5 . 2 . 3 V i c k e r s h a r d n e s s t e s t i n g m a c h i n e s s h a l l b e c o n s i d -e r e d v e r i f i e d i f t h e m e a n d i a g o n a l f o r five h a r d n e s s i m p r e s s i o n s m e e t s t h e r e q u i r e m e n t s o f 1 7 . 2 .

16. Procedure for Periodic Checks by the User 1 6 . 1 V e r i f i c a t i o n b y t h e s t a n d a r d i z e d t e s t b l o c k m e t h o d

( 1 5 . 2 . 2 ) i s t o o l e n g t h y f o r d a i l y u s e . I n s t e a d t h e f o l l o w i n g i s r e c o m m e n d e d :

1 6 . 1 . 1 M a k e a t l e a s t o n e r o u t i n e c h e c k e a c h d a y t h a t t h e t e s t i n g m a c h i n e i s u s e d .

1 6 . 1 . 2 B e f o r e m a k i n g t h e c h e c k , v e r i f y t h a t t h e z e r o r e a d i n g o f t h e m e a s u r i n g a p p a r a t u s i s c o r r e c t l y a d j u s t e d .

1 6 . 1 . 3 M a k e a t l e a s t five h a r d n e s s r e a d i n g s o n a s t a n d a r d -i z e d h a r d n e s s t e s t b l o c k o n t h e s c a l e a n d a t t h e h a r d n e s s l e v e l a t w h i c h t h e m a c h i n e i s b e i n g u s e d . I f t h e v a l u e s f a l l w i t h i n t h e r a n g e o f t h e s t a n d a r d i z e d h a r d n e s s t e s t b l o c k t h e m a c h i n e m a y b e r e g a r d e d a s s a t i s f a c t o r y ; i f n o t t h e m a c h i n e s h o u l d b e v e r i f i e d as d e s c r i b e d i n 1 5 . 2 . 2 .

17. Repeatability and Error 1 7 . 1 Repeatability: 1 7 . 1 . 1 F o r e a c h s t a n d a r d i z e d b l o c k , l e t d 1 , d 2 , ••• d 5 b e t h e

a r i t h m e t i c m e a n s o f t h e t w o d i a g o n a l s o f t h e i n d e n t a t i o n s , a r r a n g e d i n i n c r e a s i n g o r d e r o f m a g n i t u d e .

1 7 . 1 . 2 T h e r e p e a t a b i l i t y o f t h e m a c h i n e u n d e r t h e p a r t i c u l a r v e r i f i c a t i o n c o n d i t i o n s i s e x p r e s s e d b y t h e q u a n t i t y d 5 - d 1 .

1 7 . 2 Error: 1 7 . 2 . 1 T h e e r r o r o f t h e m a c h i n e u n d e r t h e p a r t i c u l a r v e r i f i ­

c a t i o n c o n d i t i o n s i s e x p r e s s e d b y t h e q u a n t i t y d - d , w h e r e d = ( d 1 + d 2 + ••• d 5 ) / 5 , a n d d i s t h e r e p o r t e d m e a n d i a g o n a l o f

i m p r e s s i o n s o n t h e s t a n d a r d i z e d h a r d n e s s t e s t b l o c k .

18. Assessment of Verification 1 8 . 1 Repeatability—The r e p e a t a b i l i t y o f t h e m a c h i n e v e r i ­

fied i s c o n s i d e r e d s a t i s f a c t o r y i f i t s a t i s f i e s t h e c o n d i t i o n s g i v e n i n T a b l e 7 .

1 8 . 2 Error—The m e a n d i a g o n a l f o r five i m p r e s s i o n s s h o u l d n o t d i f f e r f r o m t h e m e a n d i a g o n a l c o r r e s p o n d i n g t o t h e V i c k e r s h a r d n e s s o f t h e s t a n d a r d i z e d t e s t b l o c k b y m o r e t h a n 2 % o r 0 . 5 p m ( 0 . 0 0 0 5 m m ) , w h i c h e v e r i s g r e a t e r .

C. CALIBRATION O F STANDARD HARDNESS T E S T B L O C K S F O R V I C K E R S HARDNESS MACHINES

19. Scope 1 9 . 1 P a r t C c o v e r s t h e c a l i b r a t i o n o f s t a n d a r d i z e d h a r d n e s s

t e s t b l o c k s f o r t h e v e r i f i c a t i o n o f V i c k e r s h a r d n e s s t e s t i n g m a c h i n e s as d e s c r i b e d i n P a r t B .

T A B L E 7 R e p e a t a b i l i t y o f M a c h i n e s

Range of The Repeatability of the Machine Should

be Less Than:

Standardized Hardness of Test

Blocks

The Repeatability of the Machine Should

be Less Than:

Examples of Equivalents in Hardness Units

100 to 240, incl 4 % of dA,B 8 at 100 HV; 16 at 200 HV Over 240 to 600, incl 3 % of dA B 18 at 300 HV; 36 at 600 HV Over 600 2 % of dA,B 28 at 700 HV

Ad=(d1 + d2 + ... +d5)/5. B In all cases the repeatability is the percentage given or 1 | jm (0.001 mm),

whichever is the greater.

20. Manufacture 2 0 . 1 E a c h m e t a l b l o c k t o b e s t a n d a r d i z e d s h a l l b e n o t l e s s

t h a n V 4 i n . (6 m m ) i n t h i c k n e s s . 2 0 . 2 E a c h b l o c k s h a l l b e s p e c i a l l y p r e p a r e d a n d h e a t t r e a t e d

t o g i v e t h e n e c e s s a r y h o m o g e n e i t y a n d s t a b i l i t y o f s t r u c t u r e . 2 0 . 3 E a c h b l o c k , i f o f s t e e l , s h a l l b e d e m a g n e t i z e d b y t h e

m a n u f a c t u r e r a n d m a i n t a i n e d d e m a g n e t i z e d b y t h e u s e r . 2 0 . 4 T h e l o w e r s u r f a c e o f t h e t e s t b l o c k s h a l l h a v e a fine

g r o u n d finish. 2 0 . 5 T h e t e s t ( u p p e r ) s u r f a c e s h a l l b e p o l i s h e d a n d f r e e o f

s c r a t c h e s w h i c h w o u l d i n t e r f e r e w i t h m e a s u r e m e n t s o f t h e d i a g o n a l s o f t h e i m p r e s s i o n .

2 0 . 5 . 1 T h e m e a n s u r f a c e r o u g h n e s s h e i g h t r a t i n g s h a l l n o t e x c e e d 4 p i n . ( 0 . 0 0 0 1 m m ) c e n t e r l i n e a v e r a g e .

2 0 . 6 T o e n s u r e t h a t n o m a t e r i a l i s s u b s e q u e n t l y r e m o v e d f r o m t h e t e s t s u r f a c e o f t h e s t a n d a r d i z e d t e s t b l o c k , a n o f f i c i a l m a r k o r t h e t h i c k n e s s a t t h e t i m e o f c a l i b r a t i o n s h a l l b e m a r k e d o n t h e t e s t s u r f a c e t o a n a c c u r a c y o f 6 0 . 0 0 5 i n . ( 6 0 . 1 m m ) .

21. Standardizing Procedure 2 1 . 1 T h e s t a n d a r d i z e d h a r d n e s s t e s t b l o c k s s h a l l b e c a l i -

b r a t e d o n a V i c k e r s h a r d n e s s t e s t i n g m a c h i n e v e r i f i e d i n a c c o r d a n c e w i t h t h e r e q u i r e m e n t s o f 1 3 . 1 . 1 .

2 1 . 2 T h e m e c h a n i s m t h a t c o n t r o l s t h e a p p l i c a t i o n o f f o r c e s h o u l d e i t h e r :

2 1 . 2 . 1 E m p l o y a d e v i c e s u c h a s a s p r i n g t o r e d u c e t h e v e l o c i t y o f i n d e n t a t i o n o f t h e i n d e n t e r d u r i n g t h e p e r i o d o f i n d e n t a t i o n , o r

2 1 . 2 . 2 E m p l o y a d e v i c e t o m a i n t a i n a c o n s t a n t v e l o c i t y o f i n d e n t a t i o n o f t h e i n d e n t e r .

2 1 . 3 T h e f u l l t e s t f o r c e s h a l l b e a p p l i e d f o r 12 s.

22. Number of Indentations 2 2 . 1 A t l e a s t five a n d p r e f e r a b l y t e n r a n d o m l y d i s t r i b u t e d

i n d e n t a t i o n s s h a l l b e m a d e o n e a c h t e s t b l o c k .

23. Measurement of the Diagonals of the Indentation 2 3 . 1 T h e i l l u m i n a t i n g s y s t e m o f t h e m e a s u r i n g m i c r o s c o p e

s h a l l b e a d j u s t e d t o g i v e u n i f o r m i n t e n s i t y o v e r t h e field o f v i e w a n d m a x i m u m c o n t r a s t b e t w e e n t h e i n d e n t a t i o n a n d t h e u n d i s t r i b u t e d s u r f a c e o f t h e b l o c k .

2 3 . 2 T h e m e a s u r i n g m i c r o s c o p e s h a l l b e g r a d u a t e d t o r e a d 0 . 0 0 1 m m w i t h e s t i m a t e s m a d e t o t h e n e a r e s t 6 0 . 0 0 0 2 m m .

2 3 . 3 T h e m e a s u r i n g m i c r o s c o p e s h a l l b e c h e c k e d b y a s t a g e m i c r o m e t e r , o r b y o t h e r s u i t a b l e m e a n s , t o e n s u r e t h a t t h e d i f f e r e n c e b e t w e e n r e a d i n g s c o r r e s p o n d i n g t o a n y t w o d i v i -s i o n s o f t h e i n s t r u m e n t i s c o r r e c t w i t h i n 6 0 . 0 0 0 5 m m .

2 3 . 4 I t i s r e c o m m e n d e d t h a t e a c h i n d e n t a t i o n b e m e a s u r e d b y t w o o b s e r v e r s .

24. Repeatability 2 4 . 1 L e t d 1 , d 2 , - - - dn b e t h e m e a n v a l u e s o f t h e m e a s u r e d

d i a g o n a l s as d e t e r m i n e d b y o n e o b s e r v e r , a r r a n g e d i n i n c r e a s -i n g o r d e r o f m a g n i t u d e .

2 4 . 2 T h e r e p e a t a b i l i t y o f t h e h a r d n e s s r e a d i n g s o n t h e b l o c k i s d e f i n e d as ( d 1 0 - d 1 ) , w h e n t e n r e a d i n g s h a v e b e e n m a d e o r 1 .32 ( d 5 - d 1 ) w h e n five r e a d i n g s a r e t a k e n o n t h e b l o c k .

I I

8

E 92

25. Uniformity of Hardness 2 5 . 1 U n l e s s t h e r e p e a t a b i l i t y o f h a r d n e s s r e a d i n g s a s m e a -

s u r e d b y t h e m e a n d i a g o n a l s o f five o r t e n i m p r e s s i o n s i s w i t h i n t h e l i m i t s g i v e n i n T a b l e 8 , t h e b l o c k c a n n o t b e r e g a r d e d a s s u f f i c i e n t l y u n i f o r m f o r s t a n d a r d i z a t i o n p u r p o s e s .

T A B L E 8 R e p e a t a b i l i t y o f H a r d n e s s R e a d i n g s

Range of Standardized Hard­ The Repeatability of the Test Block ness of Test Block Readings Shall be Less Than:

100 to 240, incl 3 % of dA,B

Over 240 to 600, incl 2 % of dA B

Over 600 1.5 % of dA,B

Ad=(d1 + d2 +... +dn)/n. B In all cases the repeatability is the percentage given or 1 | m (0.001 mm),

whichever is the greater.

82 (2003) e 2

26. Marking 2 6 . 1 E a c h b l o c k s h a l l b e m a r k e d w i t h t h e f o l l o w i n g : 2 6 . 1 . 1 A r i t h m e t i c m e a n o f t h e h a r d n e s s v a l u e s f o u n d i n t h e

s t a n d a r d i z a t i o n t e s t ( s ee a l s o 3 . 4 . 2 , N o t e 1 ) . 2 6 . 1 . 2 T h e n a m e o r m a r k o f t h e s u p p l i e r , 2 6 . 1 . 3 T h e s e r i a l n u m b e r o f t h e b l o c k , a n d 2 6 . 1 . 4 T h e t h i c k n e s s o f t h e t e s t b l o c k o r a n o f f i c i a l m a r k o n

t h e t o p s u r f a c e ( see s e c t i o n 1 9 . 6 ) .

N O T E 6 — A l l o f t h e m a r k i n g s e x c e p t t h e o f f i c i a l m a r k o r t h i c k n e s s s h o u l d be p l a c e d o n t h e s i d e o f t h e b l o c k , t h e m a r k i n g s b e i n g u p r i g h t w h e n t h e t e s t s u r f a c e i s t h e u p p e r f ace .

27. Keywords 2 7 . 1 m e t a l l i c ; V i c k e r s h a r d n e s s

I I

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This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and ifnot revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards and should be addressed toASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. Ifyou feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, at the address shown below.

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