PH13-8Mo高强不锈钢在不同温度时效后的析出相及其对力学性能的影响

摘要

将PH13-8Mo高强不锈钢先在925 ℃进行固溶处理,然后再分别于510,540,550,565,595 ℃下进行时效处理,研究了不同温度时效后试验钢中析出相的种类和含量,以及析出相对试验钢力学性能的影响.结果表明:在较低温度时效后,试验钢中的析出相以六方结构的M2C为主,中温时效后的析出相为六方结构的M2C、面心立方的M23C6和Ni3Al以及体心立方结构的NiAl,高温时效后以体心立方的NiAl与面心立方的M23C6析出相为主;随着时效温度升高,析出相的含量逐渐增加,试验钢的抗拉强度与屈服强度逐渐降低,塑韧性不断提高;时效过程中析出的第二相粒子能起到阻碍位错运动的作用,从而提高试验钢的强度;试验钢在925 ℃固溶、540 ℃时效处理后可获得最佳的综合力学性能.%Solid-solution treatment was carried out on PH13-8Mo high strength stainless steel at 925 ℃, and then aging treatment was carried out at 510,540,550,565 ℃and 595 ℃ to study the type and content of precipitated phases and the effect of precipitated phase on mechanical properties of the tested steel.The results show that the precipitated phase in the tested steel mainly is M2C after aging at lower temperature, the precipitated phases are M2C, M23C6, Ni3Al and NiAl after aging at intermediate temperature, and the main precipitated phases are NiAl and M23C6 after high temperature aging.With the increase of aging temperature, the precipitated phase's content increases, and tensile strength and yield strength of the tested steel gradually decrease, while ductility and toughness continuously improve.The precipitated second particles during aging can impede dislocation movement, and thus increase strength of the tested steel.The optimum comprehensive properties can be obtained for the tested steel after quenching at 925 ℃ and then aging at 540 ℃.