High Temperature Properties Test And Research Of 9crlmo (P9) Seamless Pipe Used In Petrochemical Industry

Production technical process of BaoSteel-produced 9CrlMo (P9) seamless pipe is presented, and creep property of isothermal annealed state of that steel is studied under the temperatures of 550 degrees C, 600 degrees C, 650 degrees C, 700 degrees C. Also, isothermal extrapolation method and Larson-Miller method are employed to extrapolate creep rupture strength of the steel at the creep time of 20000h, 40000h, 60000h and 100000h. The results show that high temperature properties of BaoSteel-produced 9CrlMo (P9) seamless pipe meets the API 530 standard of USA and the 5H1T3037 standard of China's petrochemical industry, and the steel can be used in large scale petroleum cracking equipment. Meantime, the comparison of creep properties at 650 degrees C and transient elevated temperature properties at different temperatures between isothermal annealed state and normalized + tempered state of 9CrlMo (P9) seamless pipe as well as the microstructure analysis show that the normalized + tempered 9CrlMo (P9) seamless pipe presents better high temperature properties.