采用DIL805A膨胀仪测定15-5PH不锈钢马氏体相变点,通过LEICA DMIRM金相显微镜观察固溶后的组织及其原奥氏体晶粒形貌,用D8 ADVANCE XRD分析固溶处理后的物相组成及基体的晶格常数。研究表明,固溶温度的提高会造成马氏体相变点下降、原奥氏体晶粒的长大;固溶时间的延长造成Ms点先下降后上升,及原奥氏体晶粒的长大。固溶60 min时晶格常数最大,Ms点最低;固溶90 min时晶格常数降低,Ms点上升,并有NbC、Nb2C及CrNiFe等相析出。 The DIL805A dilatometer was used to measure the martensitic transformation point of 15-5PH stainless steel. The microstructure of the solution and the original austenite grain structure were observed by the LEICA DMIRM metallographic microscope. The D8 ADVANCE XRD Phase composition and matrix lattice constant. The results show that the increase of the solution temperature leads to the decrease of the martensitic transformation point and the growth of the original austenite grains. The increase of solution time leads to the increase of the Ms point first and the increase of the original austenite grains Big. When the solid solution is 60 min, the lattice constant is the highest and the Ms point is the lowest. When the solid solution is 90 min, the lattice constant decreases and Ms increases. And Nb, Nb2C and CrNiFe phases precipitate.