Specification :

Alloy structural steel: 4140
Executive standard: ASTM A29/ A29M-04
� Features and Scope:
Strength, high hardenability, toughness, and quenching small deformation, high temperature strength and high creep rupture strength. Requirements for the manufacture of high strength steel than 35CrMo and quenched forging greater cross-section, such as a big locomotive traction gears, supercharger drive gear, the rear axle, connecting rod by the load and the spring clip great, can also be used The following 2000m deep oil drill pipe joints and Salvage tools.
� Chemical Composition:
Carbon C: 0.38 ~ 0.43
Si Si: 0.15 ~ 0.35
Manganese Mn: 0.75 ~ 1.00
S S: to allow the residual content d 0.040
P P: allow the residual content d 0.030
Chromium Cr: 0.80 ~ 1.10
Ni-Ni: allow the residual content d 0.030
Copper Cu: d 0.030
allow the residual content Mo Mo: 0.15 ~ 0.25
� Mechanical Properties:
Tensile strength à b ( MPa) : e 1080 ( 110)
Yield strength às ( MPa) : e 930 ( 95)
Elongation ´ 5 ( % ) : e 12
Reduction of area È ( % ) : e 45
Impact energy Akv ( J) : e 63
Impact toughness ± kv ( J/ cm2) : e 78 ( 8)
Hardness: d 217HB
Sample size: Sample size is 25mm
rough � Heat treatment and microstructure specifications:
Heat Treatment Specification: quenching 850  , oil cooling; tempering 560  , water, oil cooling.
Microstructure: Tempered sorbite.