[Reference to the corresponding steel] 

 China GB Standard steel, 40Cr, the German DIN standard material number 1.17035/1.7045, the German DIN standard steel 41Cr4/42Gr4 the EN standard steel No. 18, British BS standard steel 41Cr4 French AFNOR standard steel 42C4, NF in France standard steel 38Cr4/41Cr4, Italian UNI standard steel 41Cr4, Belgium NBN standard steel 42Cr4 steel No. 2245, SS, Sweden, the United States steel, 5140 AISI / SAE / ASTM standards, Japanese JIS standard steel No. SCr440 (H) / SCr440 , the steel of the AISI / SAE / ASTM standards 5140, International Organization for Standardization ISO standard steel 41Cr4. 

 [Critical-point temperature] 

 (Approximate) Acm = 780 ℃ 

 [Normalizing norms] 

 Temperature of 850 to 870 ℃, the hardness of 179 ~ 229HBS. 

 Rough (cold press) softening specification] 

 Temperature of 740 to 760 ℃, heat preservation time of 4 ~ 6h, 10 ° C / h cooling rate and cooling to ≤ 600 ° C, cooled baked. 

 Hardness ≤ 163HBS before treatment Hardness ≤ 217HBS, softening the 

 [Raw iron protect swing tempered specification] 

 (670 ± 10) ℃ × 2h, with the furnace temperature (710 ± 10) ℃ × 2h, followed by furnace cooling, (670 ± 10) ℃ × 2h, with the furnace temperature (710 ± 10) ℃ × 2h, and then with furnace cooling, (670 ± 10) ℃ × 2h, with the furnace temperature, (710 ± 10) ℃ × 2h, cooling with furnace, a total of three cycles, and then cooled to 550 ° C, cooled baked. Treated hardness 153HBS. 

 [Quenched and specifications] 

 Quenching temperature of 850 ° C ± 10 ° C, oil cooling; tempering temperature is 520 ° C ± 10 ° C, water, oil, air-cooled. 

 Edit this paragraph 40Cr quenched and tempered hardness 

 The 40Cr hardness after quenching and tempering is about HRC32-36, that is probably HB330-380. 

 40Cr - 830-860 ℃ oil quenching -> 55HRC 

 Tempering at 150 ℃ - 55HRC 

 200 ℃ tempering - 53HRC 

 300 ℃ tempering - 51HRC 

 Tempered at 400 ℃ - 43HRC 

 500 ℃ tempering - 34HRC 

 550 ℃ tempering - 32HRC 

 Tempered at 600 ℃ - 28HRC 

 650 ℃ tempering - 24HRC 

 Edit this paragraph the 40cr features and uses 

 Feature 

 Modulation of carbon steel, cold heading die steel. The steel affordable, easy processing, after appropriate heat treatment to get a certain toughness, ductility and wear resistance. Normalizing the Organization for the Advancement of globalization to improve the hardness of less than 160HBS rough cutting performance. Tempering temperature of 550 to 570 ℃, the steel has the best mechanical properties. Hardenability of the steel is higher than 45 steel, suitable for frequency hardening, flame hardening, surface hardening treatment. 

 Use 

 Steel quenched after for the manufacture of mechanical parts of the work under medium load and medium speed, such as car steering knuckles, rear axle and the machine tools of the gear, shaft, worm, spline shaft, the top set and so on; quenched under high load, impact and medium speed parts such as gears, spindles, pump rotor, the slider rings used in the manufacture and tempering; by quenching and tempering for the manufacture of heavy duty, low impact and abrasion resistance, the cross section on the part of the entity thickness less than 25mm, such as the worm shaft, spindle, ring, etc.; used in the manufacture of high surface hardness and wear resistance after quenching and tempering and high-frequency surface hardening and no great impact on the parts such as gears, sleeves, shaft, spindle, crank, mandrels, pins, connecting rods, screws, nuts, intake valve and so on. In addition, this steel is suitable for the manufacture of carbonitriding processing, transmission parts, such as large diameter and low-temperature toughness, good gear and shaft. 

 [Supplier status and hardness] 

 Annealed, hardness ≤ 207HBS.