高强管道用1Cr16Ni4Mo2N不锈钢的热处理与组织性能研究

Study on heat treatment and microstructure and properties of1Cr16Ni4Mo2N stainless steel for high-strength pipeline

为了提升高强管道用不锈钢的力学性能和耐腐蚀性能,对高强管道用1Cr16Ni4Mo2N不锈钢进行了固溶和时效处理,研究了时效温度对不锈钢显微组织、力学性能和耐腐蚀性能的影响,并分析了其作用机理。结果表明,1Cr16Ni4Mo2N不锈钢在350~625℃时效处理4 h后,基体组织均为马氏体和奥氏体,且随着时效温度升高,马氏体向奥氏体转变;不锈钢的屈服强度ReL和抗拉强度R_(m)随着时效温度的升高先增大后减小,在时效温度为350℃时具有较高的强塑性。FeCl_(3)溶液中浸泡腐蚀试验结果与电化学试验结果一致,1Cr16Ni4Mo2N不锈钢的腐蚀速率随着时效温度的升高先增大后减小,在时效温度为350℃时具有最佳的耐腐蚀性能。因此,高强管道用1Cr16Ni4Mo2N不锈钢最佳的时效温度为350℃,此时不锈钢具有良好的强塑性和耐腐蚀性能。

In order to improve the mechanical properties and corrosion resistance properties of stainless steel for high-strength pipelines,the solution and aging treatment on 1Cr16Ni4Mo2N stainless steel for high-strength pipeline was conducted,the influences of aging tem-perature on the microstructure,mechanical properties and corrosion resistance properties of stainless steel were studied,and its mechanism of action was analyzed.The results show that after aging treatment at 350-625℃for 4 hours,the matrix structures of 1Cr16Ni4Mo2N stainless steel are martensite and austenite,and with the increasing of aging temperature,martensite transforms into austenite.The yield strength R_(eL) and tensile strength R_(m) of 1Cr16Ni4Mo2N stainless steel first increases and then decreases with the increasing of aging temper-ature,which has good strength plasticity at the aging temperature of 350 C.The results of immersion corrosion test in FeCl_(3) solution are consistent with those of electrochemical test.The corrosion rate of 1Cr16Ni4Mo2N stainless steel first increases and then decreases with the increasing of aging temperature,and it has the best corrosion resistance property at the aging temperature of 350 C.Thus,the opti-mum aging temperature of 1Cr16Ni4Mo2N stainless steel for high-strength pipeline is 350 C,at this time,the stainless steel has good strength and plasticity as well as corrosion resistance property.