热处理工艺对X22CrMoV12-1钢组织和性能的影响

Effect of Heat Treatment Process on Microstructures and Mechanical Properties of X22CrMoV12-1 Steel

X22CrMoV12-1属于马氏体不锈钢,常用于制作透平叶片。对尺寸为φ25 mm×65 mm的X22CrMoV12-1钢试块进行了不同工艺的热处理:(1)从1 000～1 090℃油冷,680℃回火空冷;(2)从1 030℃炉冷、空冷、风冷、油冷和水冷;(3)从1 030℃油冷,650～710℃回火空冷;(4)从1 030℃油冷,680℃回火,随后炉冷、空冷、风冷、油冷和水冷;(5)从1 030℃油冷,680℃空冷和640～680℃空冷两次回火。检测了热处理后钢的显微组织和力学性能。结果为:淬火温度对钢的力学性能影响较小;淬火速率增大,钢的冲击韧度提高,韧-脆转变温度(FATT50)下降,但对强度的影响不明显;回火温度提高,钢的强度、FATT50下降,冲击韧度提高;回火后的冷却速度增大,钢的冲击韧度提高,FATT50下降,但对强度影响不大;在比第一次回火温度低(a)0～10℃和(b)20～30℃的温度第二次回火对钢的力学性能影响(a)较大和(b)较小。

X22CrMoV12-1 belongs to martensite steel, and is commonly used to make turbine blade. The test X22 CrMoV12-1 block 25 mm in diameter by 65 mm long was heat treated as follows：（ 1） oil-quenching from temperatures ranging from 1 000 to 1 090 ℃ followed by tempering at 680 ℃ and air-cooling;（2） cooling in furnace, air, and in forced air, and quenching in oil and in water from 1 030 ℃, followed by tempering at 680 ℃and air-cooling;（3） oil-quenching from 1 030 ℃ followed by tempering at a temperature ranging from 650 to 710 ℃and air-cooling;（4） oil-quenching from 1 030 ℃, followed by tempering at 680 ℃ and cooling in furnace, air,forced air, oil, and water;（5） oil-quenching from 1 030 ℃, followed by two separate tempering treatments at680 ℃ for the first operation and 640 to 680 ℃ for the second operation and air-cooling. After the heat treatment the microstructure and mechanical properties of the steel were checked. The results were that ： austenitizing temperatures had no obvious influence on mechanical properties of the steel; as the quenching rate increased, the impact toughness rose, fracture appearance transition temperature（ FATT50） decreased,but the strength had no appreciable change; as the tempering temperature became higher, the strength and FATT50 decreased, the impact toughness rose;with the increase in cooling rate from tempering temperature, the impact toughness rose, FATT50 decreased, but the strength had no appreciable change;the second tempering at temperatures（a） 0 to 10 ℃ and（b） 20 to 30 ℃ lower than that of the first tempering had more obvious influence for（a） and less obvious influence for（b） on mechanical properties of the steel.