What is Material AISI 4140/4142, DIN 41CrMo4/42CrMo4 Heat Treatment Process and Hardness Property

A brief introduction to 42CRMO4 material

42CrMo steel is an ultra-high strength steel with high strength and toughness, good hardenability, no obvious temper brittleness, high fatigue limit and multiple impact resistance after quenching and tempering treatment, and good low temperature impact toughness. 42CrMo steel is suitable for manufacturing products that require certain strength and toughness. 42CrMo steel is also well known as AISI 4140/4142 also.

42CrMo steel has superior low temperature performance, material 42CrMo can pass the -60°C impact test, while general ST52 can only pass the -20°C impact test according to standard DIN 2391 (EN 10305-1), if it need higher low temperature performance, it will need to use 42CrMo.

Equivalent International Standards for 42CrMo steel

42CrMo Heat Treatment Process and Hardness Property：

Annealing annealing No.1 “760±10℃ annealing, furnace cooling to 400℃ air cooling, Hardness HB220-230

Quenching+tempering No.5 840±10℃ quenching water or oil (depending on the complexity of the product shape), tempering at 680-700 degrees. Hardness HB<217

Quenching+tempering No.6 840±10℃ quenching oil, and then 470 degree tempering treatment, Hardness HRC41-45.

Quenching+tempering No.7 quenching oil at 840±10℃, and then tempering at 480℃. , Hardness HRC35-45.

Quenching+tempering No.8 quenching oil at 850℃, then tempering at 510℃, Hardness HRC38-42.

Quenching+tempering No.9 quenching oil at 850℃, and then tempering at 500℃,Hardness  HRC40-43.

Quenching+tempering No.10 quenching oil at 850℃, and then tempering at 510℃, Hardness HRC36-42.

Quenching+tempering No.11 850 ℃ quenching oil, and then 560 ℃ tempering treatment, Hardness HRC32-36.

Quenching+tempering No.12 Oil quenching at 860°C, and then tempering at 390°C, Hardness  HRC48-52.

Applications:

42CrMo is widely used in the production of honed pipe, chrome plated rods and other hydraulic cylinder parts, especially in the hydraulic system under low temperature working environment, which is widely used in Siberia, Russia.

Here below is our product range of the 42CrMo /AISI 4140/4142 steel.

42CrMo / 4140 Chrome Plated Rod

42CrMo /4140 Chrome Plated Tubing

42CrMo / 4140 Hard Chrome Plate Shafts

42CrMo / 4140 Honed tubes

Contact us to get a quote and more details.