固溶温度对低镍奥氏体不锈钢组织与性能的影响

Effects of Solution Temperature on Microstructure and Properties of Low Nickel Austenitic Stainless Steel

利用光学显微镜(OM)、扫描电镜(SEM)、万能材料试验机、电化学工作站等设备研究了1 000~1 200℃固溶温度区间低镍奥氏体不锈钢的组织演变、力学性能及耐腐蚀性能。结果表明,当温度从1 000℃升至1 050℃时,奥氏体含量上升,铁素体含量降低;到1 050℃后,随温度升高奥氏体含量降低,铁素体含量升高,1 200℃时铁素体含量明显升高且晶粒度减小。另外,固溶温度对抗拉强度影响不明显,在1 050℃时抗拉强度为780MPa。固溶温度对伸长率影响明显,在1 200℃固溶时伸长率最高,达39.98%。极化曲线测试表明,在1 150℃固溶时不锈钢的腐蚀电流密度为6.637μA·cm-2,耐蚀性最好。

The microstructure evolution,mechanical properties and corrosion resistance of low nickel austenitic stainless steel were investigated by means of optical microscope(OM),scanning electron microscope(SEM),universal material testing machine and electrochemical workstation within the solution temperature range from 1 000℃to 1 200℃.The results reveal that the austenite content is increased and the ferrite content is decreased with the temperature rising from 1 000℃to 1 050℃.After 1 050℃,the austenite content is decreased and the ferrite content is increased with the increase of temperature.The ferrite content is increased obviously and the grain size is decreased at 1 200℃.The tensile results show that the solution temperature has a little effect on the tensile strength,which has the highest value of 780 MPa at 1 050℃,while has a great influence on the elongation,which has the highest value of 39.98%at 1 200℃.The polarization curve test shows that the alloy has the desirable corrosion resistance at 1 150℃,where the value of corrosion current density reaches 6.637μA·cm-2.