高强韧热作模具钢SR19的组织与力学性能

通过冲击试验、硬度测试、显微组织观察和断口分析研究了不同淬火、回火工艺对SR19热作模具钢微观组织及力学性能的影响,并与H13钢进行了对比。结果表明:960~1060 ℃温度范围内淬火时,SR19钢的硬度比H13钢高3~4 HRC;在高于540 ℃回火时,相同温度下SR19钢的硬度比H13钢要高0.5~1.0 HRC,且SR19钢回火后的冲击吸收能量比H13高40~50 J。增Mo加W增加了纳米析出相的数量,提高了抗回火软化能力和冲击性能。SR19钢的最佳热处理工艺为1020 ℃油淬、560~600 ℃回火,此工艺下的硬度为50.9~54.8 HRC。

Microstructure and mechanical properties of high strength and toughness hot die steel SR19

Microstructure and mechanical properties of hot die steel SR19 under different quenching and tempering processes were studied and compared with H13 steel by means of impact test, hardness test, microstructure observation and fracture analysis. The results show that when quenching at 960-1060 ℃, the hardness of SR19 steel is 3-4 HRC higher than that of H13 steel. When tempered at higher than 540 ℃, the hardness of SR19 steel is 0.5-1.0 HRC higher than that of H13 steel at the same tempering temperature, meanwhile, the impact absorbed energy of SR19 steel is 40-50 J higher than that of H13 steel. The addition of Mo and W increases the amount of nano-precipitated phase, improves the temper softening resistance, and makes the dimple of impact fracture smaller. The optimum heat treatment process of the tested steel is oil quenched at 1020 ℃, tempered at 560-600 ℃, by which the optimum hardness is 50.9-54.8 HRC.