Effect of Tempering Treatment on Microstructure and Properties of ZG04Cr13Ni4 Martensitic Stainless Steel Castings

Author of the article:SUN Lan 1 , YANG Mingchuan 2 , JIANG Fan 1 , XIAN Guang 1 , FAN Hongyuan 1

Author's Workplace：1. School of Mechanical Engineering, Sichuan University, 2.China Construction Steel Structure Engineering Co., Ltd.,

Key Words：04Cr13Ni4; martensitic stainless steel; tempering temperature; heat treatment; mechanical property

Abstract：The microstructure and mechanical properties of ZG04Cr13Ni4 martensitic stainless steel commonly used for
800-1000 MW water turbine runner were studied at different tempering temperatures and times. The results show that
the microstructure of ZG04Cr13Ni4 martensitic stainless steel after normalizing and primary or secondary tempering is
strip martensite and has obvious original austenite grain boundary. When the secondary tempering temperature increases
further, the lath martensite becomes coarser, but still retains the orientation and morphology of martensite lath. After
normalizing and secondary tempering, the comprehensive mechanical properties of the materials are significantly
improved. The best heat treatment process is normalizing and secondary tempering process, and the tempering
temperature is controlled between 600 ℃ and 640 ℃ , which can meet the mechanical properties requirements of
product industry standards.