Heat treat AISI 4142 material
Heat treat AISI 4142 material
(OP)
I have to heat treat AISI 4142 material and meet a minimum tensile of 143,000 and (here's the kicker) we need to run charpy tests at -40 and obtain 25-mils lateral expansion. In the AISI 4142 range of chemistry allowed by ASTM A-540 B22, what elements will give me a better chance of meeting this (High C, low P & S, High Mo etc.) ?
The finished material specification A-540 requires a minimum tempering temp of 850 F.
If any one has performed a heat treat and met this I'd like to correspond w/you. Thanks in advance for your time.
The finished material specification A-540 requires a minimum tempering temp of 850 F.
If any one has performed a heat treat and met this I'd like to correspond w/you. Thanks in advance for your time.





RE: Heat treat AISI 4142 material
I would not change a thing regarding chemistry ( one exception; lower carbon is better because of the direct affect on notch toughness), expect make sure you have a tempered martensite structure throughout. Quench in oil and temper at 1100 deg F. The tempered martensite structure of 4142 should meet the impact requirements.
For 4140 Q&T
1100 deg F
148 UTS Ksi
132 YS Ksi
19.0 % E (2" gage)
58% RA
311 BHN
69 ft-lbs at RT
RE: Heat treat AISI 4142 material
"When the eagles are silent, the parrots begin to jabber."
Winston Churchill