4-1 4-2 4-3 4-4

4-1 (specific gravity)4 C > 1 () > 4 < 4

(specific heat)11 C(calorie)

(/C)6.2(mole)1 C(atomic heat)(Dulong and Petit rule)

(coefficient of thermal expansion)1 C

(thermal conductivity)1 cmCcm2

()

(specific resistance)1 cm21 cmohm-cm

(magnetism)

(hard magnet)

1. (ferromagnetism)

(Gd)AlnicoCunife MnBi

(soft magnet)()

(ferrimagnetism) TbFe2 GdCo2

2. (paramagnetism)

MgCaSrBaAl

3. (diamagnetism)

CuAgAuZn

()(Curie point)()500 C600 C768 C768 C358 C1131 C16 C

()()

(BCC)(FCC)

B = HH(Oe)

B(G)(permeability)

< 1 > 1(

)

4-2

4-2-1 (oxidation)

E = (volt)M

n13e

E

+ + neMM n

E25 C1 M ()1 atm( )

(pp. 76, 4-2NiE)E

()MO(s) + 2H2O(l) M++(aq) + 2OH(aq) + H2(g)

OHE

EE

221 HeH + +

E

4-2-2 (corrosion)

(erosion-corrosion) (stress-corrosion) (corrosion-fatigue)

(corrosion medium)

(scaling)

1.

(electro-chemical attack)()

2.

3.

Fe2O34Fe + 3O2 2Fe2O3

Fe2O3

2Fe + O2 2FeOFeO560 CFe3O4FeO560 C

4FeO 2Fe3O4 + Fe t

t

C560

E

1. 2. 3.

(anodic area)(cathodic area)H+

1.

2. ()

(inhibitor)

4-3

(stress)

(kgf/mm2)(N/m2Pa)psi(pound per square inch)1 kgf/mm2 = 1422 psi = 9.806 MPa (M106)1 MPa = 0.102 kgf/mm21 ksi = 1000 psi

(strain)

1. cmcmcm/cm2.

(elasticity)

(plasticity)(elastic limit)

(modulus of elasticity)

(stiffness)

(strength)

(tensile strength)(tensile test)

(yield strength)

(compressive strength)

(torsional strength)

(shear strength)50 %

(fatigue strength)

(creep strength)

(creep)

(impact strength)()

(hardness)

(ductility)

(elongation) (%) =

(reduction in area) (%) =

%100

%100

(malleability)

(toughness)

kgfm/cm2

4-4

4-4-1

CNSJISASTMDIN

4-4-2 ()

(specimen)(yield point)

CNS14114(CNS 2112G2014)

()(strain gauge)(necking)

()

Baldwin-Tate-Emery

E

()(proportional limit)()()#1Y1(yielding)Y1Y2Y2Y1Y2#3#2(off-set method)#2(0.2 %)R #1 C (ultimate tensile

strengthUTS)()

= K (K)

= K () ()= K (cm/cm) (kgf/cm2)= K kgf-cm/cm3

kgf-cmcm3

(cup and cone)

4-4-3

(indenter)

()

1. (Brinell Hardness Testing)2. (Rockness Hardness Testing)3. (Vickers Hardness Testing)4. (Shore Scleroscope Test)

mm(BHNHB)PDd

2/)()()()(

222 DdDDP

mmkgHBHN B

==

3000 kg()500 kg()10 mm()15302

BHN 450 (10/3000/15)

10 mm6 mm5 mm3 mm

hBHN

d(h)BHN

BHN70~500BHN 800

()

DhPBHN

=

1200.2 mm

(Brale)1.6~12.7 mm (1/16 ~ 1/2)

(Rockwell superficial tester)122742 kg3 kg

1 m

(minor load)()SET(major load)10 kg5090140 kg

B()

B90 kgHRBC()

C150 kgHRC100 1/500 mm

CB30 t t/(1/500)

500tHRC = 100 500tHRB = 130 500t

ADEFGH

()

()1 kg120 kg103050 kg

PDmm()Hv

Hv = 2 sin 68 (P/D2) = 1.854 P/D2

(Micro-Vickers Hardness Tester)()

Knoop(5~500 g)

()()

(h0)(h)(Hs)

Hs100

06510000

hhH s =

(Magnifier Hammer)

(Testing Hammer)

(BHN)

BHN 10 HRC (BHN300 ~ 600)BHN 6 HS ()HV BHN + 20 (H < 450)T.S. () 35 BHN ()

()

(workability)

4-1 4-2 4-3 4-4