氮对0.3C-26Cr-8Ni耐热钢组织与性能的影响

Effect of Nitrogen on Structure and Properties of Heat-Resistance Steel 0.3C-26Cr-8Ni

采用酸碱滴定法分析0．3C-26Cr-8Ni钢中铸态和1250℃高温拉伸后的固溶氮量和化含氮量,探讨了氮的存在形式与钢的拉伸性能的关系。结果表明,铸态和高温拉伸后氮大部分以化合态形式存在,高温拉伸中,随氯化物的析出使氮固溶量降低。随着氮加入量的增加．合金室温延伸率下降．但室温强度和高温强度、高温延伸率均呈先上升后下降的规律。

The relation between the existence form of nitrogen and tensile properties of 0. 3C-26Cr-8Ni steel has been studied by analyzing the solid-solution and compound nitrogen in alloy casted and high-tempera-ture tensioned using acid and alkali titration. The results showed that in as-cast steel high-temperature ten-sioned the nitrogen mainly exists in form of nitride; and the solid-solution nitrogen content further decreases with increasing precipitation of nitride during high temperature tensioning, and with increasing the amount ad-dition of nitrogen the ambient elongation decreases, at the same time the ambient strength as well as the high temperature strength and elongation increase obviously as nitrogen content in steel is less than 0. 25%, and then decrease.