904L钢高温下固溶-析出行为及析出相规律

为了研究904L钢高温下固溶析出行为及其析出相演变规律,采用热处理试验炉,对中试试验生产的904L钢热轧板进行了不同温度、不同时间下的固溶处理;对固溶处理后的试样在900℃下分别进行不同时间的时效处理。结果表明,经固溶处理后904L钢晶界处的高温析出相已基本溶解固溶于基体中,组织为单一的奥氏体组织,未出现明显第二相组织,但由于固溶不充分、钼元素存在条带状偏析,且出现少量孪晶,随着固溶温度升高和固溶时间的延长,晶粒尺寸逐渐增加,1 135℃、600s固溶处理后组织和性能较好;固溶处理后的试样在900℃高温下经不同时间时效处理后,基体中均析出σ相,随着时效时间延长,基体中σ析出相逐渐增多,尺寸也逐渐增大,并且有粗化趋势。

Solid solution precipitation behavior and rule of precipitate phase of 904L steel at high temperature

In order to study the solid solution precipitation behavior and the precipitates evolution of 904L steel at high temperature， the hot rolled 904L steel sheets produced in pilot plant for solution treatment at different temperatures and times in a heat treatment furnace were studied. The aging treatment of the samples treated by solution treatment was carried out. The results showed that the high temperature precipitates dissolved in the matrix after solution treatment. The microstructure was single austenite and the second phase structure did not appear. However，the microstructure had the segregation strip of Mo element due to insufficient solution and the microstructure also had a small amount of twin crystal. With the solution temperature and solution time increasing，the grain size grew. The samples had good microstructure and properties after solution treatment at 1 135 ℃ for 600 s. There were some σ phase precipitates after solution treatment at 900 ℃ for different time in the matrix. With the aging time increasing，the quantities and sizes of σ phase in the matrix increased gradually，and the σ phase had coarsening trend.