1
VACUUM Classified Abstracts 0 0 I -- General Science and Engineering -- I Contd. methods of analysing the extracted gases. The first part of the article is sub-divided into methods of extracting oxygen, hydrogen ,and nitrogen. Details are given of the oxygen extraction method developed by Chaudron and Moreau, Sloman's apparatus and Chaussain's apparatus. The main feature of all these methods is that the steel is heated to a temperature of 1,600°C under vacuum at which temperature it is known that all oxides are completely reduced. Hydrogen present in steel is not chemically combined with the metal; its extraction can be effected in various ways : (a) By volumetric measurement of the hydrogen liberated at ordinary temperature, (b) by applying a heat of 1050°C under vacuum, (c) by vacuum fusion at high temperature, (d) by ion bombard- ment, (e) by heat treatment at comparatively low temperatures (approximately 600°C). Methods based on the latter have been developed by Newell, Cotbeck and Craven and Bastien. A short description of each of these methods is given. Nitrogen content can be determined by the vacuum fusion method but in the opinion of the author chemical methods such as the one devised by Rocquet-Olette give better results. In the second part of the article the author gives a short description of the folIowing methods available for the analysis of extracted gases : The apparatus proposed by Lebeau and Damiens, Podbielniack's method, the Nash method, and the mass spectrometer method. Sommaire : L'auteur ddcrit tout d'abord les appareils utilis4s pour l'extraction des diff4rents gaz : oxygene hydrog6ne, azote. I1 4tudie ensuite Ies dispositifs analyseurs I6 Per Cent Aluminium-Iron Alloy Cold Rolled in the Order--Disorder Temperature Range United States. The aluminium-iron alloys are known to have sound magnetic properties and require no materials in critical supply for their production. But their development is retarded because in fabrication these materials show great brittleness. This applies in particular to the 16% aluminium-iron alloy. The present article reports details of a series of experiments, in the course of which 16% aluminium-iron alloy with good ductility and sound magnetic properties was produced and fabricated successfully. For the production of the material electrolytic iron was melted in a magnesium oxide crucible in a pressure-vacuum furnace of 30 lb capacity. The pressure at the start of the melting was 200/z but rose in the course of melting due to the liberation of gasas. The molten iron was decarburised with wet hydrogen and subsequently deoxidised with dry hydrogen On completion of the hydrogen treatment the hydrogen was purged from the chamber with pure dry helium, followed by evacuation of the furnace to remove hydrogen dissolved in the melt. The aluminium was added to themelt after re-fillingthe furnace with helium. The materialwas cast into ingots of the dimensions 10×5×1 inch. The first fabrication process was hot-rolling. The temperature Was 1,000°C and the heat was applied to the slab one hour prior to the start of the rolling process. This temperature promotes the formation of large grains in the material. Hot-rolling was continued down to a thickness of 0.125 inch of the slab. The aluminium- iron phase diagram shows that 10-20% of aluminium alloyed to iron tends to order irito an FeaAI type lattice. Consequently it was decided to heat-treat and cool the hot-rolled material appropriately and then to cold-roll it at three different temperatures, 500°C, 550°C and 575°C. The temperature of 575°C is just above the order disorder temperature-range and has given the most satisfactory results in the experiments. Cold rolling at 575°C can be continned down to a thickness of 0.007 inch. Photomicrographs of the end product show a highly fibred structure indicative of toughness and ductility. .Special techniques are described which facilitate further reduction of thickness by roiling at room temperatures down to 0.0005 inch thickness. The magnetic properties of cold-rolled 16% aluminium-iron alloys after various heat treatments are shown in a table partly reproduced below. Magnetic Properties of Cold-Rolled 16 Percent All-Fe Alloys after Various Heat Treatments ~ eci~en No. i;97- 1992X 2045 2045X Thickness of laminations 0.014 inch 0.014 inch 0.007 inch 0.007 inch /*2O -~4~- 2778 412'7 4158 d.c. magneti~pr( ~m B2~ 15 000 0.024 86 300 0.040 77 800 0.044 ~erties -- 3-;G- 4200 4000 4000 Bm b 7600 770 8000 Heat Treatment FH to /,000°C--hold 2 hours. FC to 600°C---hold 10 minutes. RC FH to 900°C hold k hour. FC to 600°C--hold 10 minutes. Water quench FIt to 900°C--hold 1 hour. FC to 600°C--hold 10 minutes. Water quench FH to 1,000°C--hold 2 hours. FC to 600°C--hold 10 minutes. Water quench FH--heated with furnace. FC--cooled with furnace. RC--withdrawn rapidly from heat gone to front of furnace. Sommaire : On donne des d6tails sur la pr6paration d'uh alliage de fer et de 15% d'aluminium, qui est faite duns un four ~ vide d'une capacit6 de 20 kg environ. A Remarkable Etching of Copper See Abstract No. : 83/I Magnesium Housings . . . Vacuum Impregnated See Abstract No. : 77/III Abstract No. and References Article by J. Amoignon Le Vide 9, Jan. 1954 1462-1469 133/I Article by J. F. Nachman & W. J. Buehlcr J. APT1. Phys. 25, March 1954 307-313 134/I 135fl April, 7954 Vacuum 229 Vol. IV No. 2

Magnesium housings … vauum impregnated

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V A C U U M

Classified A b s t r a c t s

0

0

I - - G e n e r a l S c i e n c e a n d E n g i n e e r i n g - - I Contd.

m e t h o d s of ana lys ing t he ex t r ac t ed gases. The first p a r t of t he art icle is sub-d iv ided into m e t h o d s of e x t r a c t i n g oxygen, h y d r o g e n ,and ni t rogen. Deta i l s are g iven of t he oxygen ex t r ac t i on m e t h o d developed by Chaud ron and Moreau, S loman ' s a p p a r a t u s and C h a u s s a i n ' s a p p a r a t u s . The m a i n fea ture of all these m e t h o d s is t h a t t he steel is hea t ed to a t e m p e r a t u r e of 1,600°C unde r v a c u u m at which t e m p e r a t u r e i t is k n o w n t h a t all oxides are comple te ly reduced. H y d r o g e n p re sen t in steel is no t chemica l ly combined w i th t he me ta l ; i t s ex t r ac t i on can be effected in va r ious ways : (a) B y vo lumet r i c m e a s u r e m e n t of t he h y d r o g e n l iberated a t o rd ina ry t e m p e r a t u r e , (b) b y app ly ing a h e a t of 1050°C unde r v a c u u m , (c) b y v a c u u m fus ion a t h igh t e m p e r a t u r e , (d) b y ion b o m b a r d - men t , (e) by h e a t t r e a t m e n t a t c o m p a r a t i v e l y low t e m p e r a t u r e s ( app rox ima te ly 600°C). Methods based on t he l a t t e r have been developed by Newell, Cotbeck and Craven and Bas t ien . A shor t descr ip t ion of each of these m e t h o d s is given. Ni t rogen con t en t can be de t e rmined b y t he v a c u u m fus ion m e t h o d b u t in t he opinion of t he a u t h o r chemical m e t h o d s such as t he one devised b y Rocque t -Ole t t e give be t t e r resul ts . I n t he second pa r t of t he art icle t he a u t h o r gives a shor t descr ip t ion of t h e folIowing m e t h o d s avai lable for t he analys is of ex t r ac t ed gases : The a p p a r a t u s proposed b y L ebeau and Damiens , Podbie ln iack ' s me thod , the N a s h me thod , and t he mass spec t romete r me t hod .

Sommaire : L ' a u t e u r ddcrit t o u t d ' abo rd les appare i l s uti l is4s pour l ' ex t rac t ion des di f f4rents gaz : oxygene hydrog6ne , azote. I1 4tudie ensu i te Ies disposi t i fs ana ly seu r s

I6 Per Cent A l u m i n i u m - I r o n Alloy Cold Rolled in the Order- -Disorder Temperature R a n g e

United States. The a l u m i n i u m - i r o n al loys are k n o w n to have sound m a g n e t i c proper t ies and require no ma te r i a l s in cri t ical supp l y for thei r p roduc t ion . B u t the i r deve lopmen t is r e t a rded because in fabr ica t ion these ma te r i a l s show grea t br i t t leness . This appl ies in pa r t i cu la r to t he 16% a lumin ium- i ron alloy. The p re sen t art icle repor t s deta i ls of a series of exper imen t s , in t he course of wh ich 16% a lumin ium- i ron al loy wi th good duc t i l i ty and sound m a g n e t i c proper t ies was p roduced and fabr ica ted successfully. For t he p roduc t ion of t he ma te r i a l e lectrolyt ic iron was mel ted in a m a g n e s i u m oxide crucible in a p r e s s u r e - v a c u u m furnace of 30 lb capac i ty . The pressure a t t he s t a r t of t he me l t i ng was 200/z b u t rose in t he course of me l t i ng due to t h e l ibera t ion of gasas. The mol t en i ron was decarbur i sed wi th wet h y d r o g e n and s u b s e q u e n t l y deoxidised wi th d ry h y d r o g e n On comple t ion of t h e h y d r o g e n t r e a t m e n t t he h y d r o g e n was pu rged f rom the c h a m b e r wi th pure d ry he l ium, followed b y evacua t i on of the fu rnace to r emove h y d r o g e n dissolved in t he melt . The a l u m i n i u m was added to t h e m e l t af ter re - f i l l ing the fu rnace wi th hel ium. The m a t e r i a l w a s cas t into ingots of the d imens ions 1 0 × 5 × 1 inch. The first fabr ica t ion process was hot-rol l ing. The t e m p e r a t u r e Was 1,000°C and t he hea t was applied to t he slab one hou r pr ior to t he s t a r t of t he rolling process. This t e m p e r a t u r e p romo te s the fo rma t ion of large grains in t he mater ia l . Hot - ro l l ing was con t inued down to a th i ckness of 0.125 inch of the slab. The a l u m i n i u m - i ron phase d i a g r a m shows t h a t 10-20% of a l u m i n i u m alloyed to i ron t ends to order irito an FeaAI t ype latt ice. Consequen t ly i t was decided to h e a t - t r e a t and cool t he hot-rol led ma te r i a l appropr ia te ly and t h e n to cold-roll i t a t t h ree di f ferent t empe ra t u r e s , 500°C, 550°C and 575°C. The t e m p e r a t u r e of 575°C is j u s t above t he order

disorder t e m p e r a t u r e - r a n g e and ha s g iven t he m o s t sa t i s fac to ry resu l t s in t he exper iments . Cold roll ing a t 575°C can be con t inned down to a th i ckness of 0.007 inch. P h o t o m i c r o g r a p h s of t he end p roduc t show a h igh ly f ibred s t r uc tu r e ind ica t ive of t o u g h n e s s and duct i l i ty . .Special t e chn iques are described which faci l i tate fu r the r r educ t ion of th i ckness b y roil ing a t room t e m p e r a t u r e s down to 0.0005 inch th ickness . The m a g n e t i c proper t ies of cold-rolled 16% a l u m i n i u m - i r o n alloys af ter var ious h e a t t r e a t m e n t s are shown in a table pa r t l y reproduced below.

Magnetic Properties of Cold-Rolled 16 Percent All-Fe Alloys after Various Heat Treatments

~ e c i ~ e n

No.

i ; 9 7 -

1992X

2045

2045X

Thickness of laminations

0.014 inch

0.014 inch

0.007 inch

0.007 inch

/*2O

-~4~- 2778

412'7

4158

d.c. magneti~pr( ~m B2~

15 000 0.024

86 300 0.040

77 800 0.044

~erties

- - 3-;G-

4200

4000

4000

Bm b

7600

770

8000

Heat Treatment

FH to /,000°C--hold 2 hours. FC to 600°C---hold 10 minutes. RC FH to 900°C hold k hour. FC to 600°C--hold 10 minutes. Water quench FIt to 900°C--hold 1 hour. FC to 600°C--hold 10 minutes. Water quench FH to 1,000°C--hold 2 hours. FC to 600°C--hold 10 minutes. Water quench

FH--heated with furnace. FC--cooled with furnace. RC--withdrawn rapidly from heat gone to front of furnace. Sommaire : On donne des d6tails sur la p r6para t ion d ' u h alliage de fer et de 15% d ' a l u m i n i u m , qui est fai te duns u n four ~ v ide d ' u n e capaci t6 de 20 kg envi ron .

A Remarkab le E tch ing of Copper

See A b s t r a c t No. : 83 / I

M a g n e s i u m Hous ings . . . V a c u u m Impregnated

See A b s t r a c t No. : 77 / I I I

Abstract No. and References

Article by J. Amoignon

Le Vide 9, Jan. 1954

1462-1469

133/I

Article by J. F. Nachman &

W. J. Buehlcr J. APT1. Phys.

25, March 1954 307-313

134/I

135fl

April, 7954 Vacuum 229 Vol. I V No. 2