热处理工艺对38CrMoAlA钢组织与性能的影响

 通过热处理工艺试验研究了38CrMoAlA钢不同淬火温度、冷却方式和回火温度对38CrMoAlA钢微观组织及力学性能的影响。结果表明,在900—1000℃淬火温度范围内,淬火温度对该钢的力学性能影响不大。不同的冷却方式因淬火介质的冷却强度不同,导致淬火后的组织不同,从而影响该钢的力学性能。回火温度对该钢的力学性能的影响较为显著,100—400℃范围内回火表现出回火脆性,在620℃回火能得到较好的强韧配合。该钢采用940℃,1h,油冷620℃,5h,油冷的热处理工艺时,可获得适宜的力学性能。

Effect of Heat Treatment Process on Microstructure and Mechanical Property of 38CrMoAlA Steel

The effects of quenching temperature, cooling method and tempering temperature on the microstructure and mechanical properties of 38CrMoAlA steel have been studied through a series of heat treatment process tests. The experiment has measured the mechanical properties of the steel in different heat treatment conditions. The mechanical tests include tensile, impact and hardness test. The experiment has also measured the continuous cooling change curve of the steel, and analyzed the microstructure of the steel under different cooling rate and different temper conditions. The results of tests show that the effect of quenching temperature on mechanical properties of the steel the impact is not big when quenching at the temperature between 900℃ and 1000℃. Because of different cooling intensity of quenching medium, different cooling methods lead to different microstructure, and thus affect the mechanical properties of the steel. The effect of tempering temperature on the microstructure and mechanical properties of the steel is the most remarkable. When tempered at the temperature between 100℃ and 400℃, it behaves temper brittlement. While tempered at about 620℃, it can get a good combination of strength and toughness. Therefore, choosing the heat treatment process of quenched by heating to 940℃, holding at temperature for one hour, cooling in oil, and tempered by heating to 620℃, holding at temperature for five hours, cooling in oil, 38CrMoAlA steel can get the best property.