4140 Steel Heat Treatment Hardness

For 4140 steel the recommended heat treatment 1 consists of heating to austenitizing temperature typically 1570 f 855 c followed by oil quenching.

4140 steel heat treatment hardness.

Alloy description timkensteel s 4140hw grade is a fine grained low alloy steel that offers optimum heat treat response in heavier cross sections. 4140hw alloy steel technical data 4140hw meets aisi4140 standards and has improved hardenability and strength in heavier cross sections. Tempering reheating after quenching will achieve the desired hardness range. For example a tensile strength of 225 ksi can be achieved by tempering at 316 c 600 f and tensile strength of 130 ksi can be achieved by tempering at 538 c 1000 f.

3 tempering recommendations from the asm heat treaters guide for 4140 4142 is a minimum of 400 f. You find 4140hw in a. This leaves near full hardness. The section size in which maximum hardness can be obtained depends on alloy content.

1 4140 is an ok die steel but is not recommended for radical shaped dies such as narrow fullering crown and so on. 4140 has a nominal carbon content of 4 and this carbon content will yield a hardness of rc 51 for a 90 martensitic structure 9th edition of the asm material handbook volume i. Aisi 4140 alloy steel can be hardened by cold working or heating and quenching. 2 fully hardened 4140 ranges from 54 to 59 hrc.

The hardness of the steel can be increased if it has a lower tempering temperature. Tempering temperature of 4140 alloy steel can be from 204 649 c 400 1200 f after normalizing and oil quenching and the corresponding rockwell hardness can be obtained.