采用真空感应炉试制3炉不同碳含量的15-5PH沉淀硬化不锈钢,通过热模拟的方法确定了该钢的板材最佳轧制温度区间为900~1100℃,研究了碳含量对钢的相变点温度及力学性能的影响,并观察了时效态的微观组织。结果表明,随着含碳量的增加钢的相变点温度逐渐降低,在时效处理后含碳量较低的1#钢强度均高于2#钢和3#钢,且具有良好的韧塑性;随着时效温度的升高,含碳量较高的2#钢,3#钢中生成的逆转变奥氏体量及生成速率均高于1#钢,这是其强度低于1#钢的主要原因,钢的时效态组织为板条马氏体+少量逆转变奥氏体组织,以及大量的、细小的富Cu相,富Cu相的析出是该钢主要的强化方式。通过上述分析,本文将1#钢的化学成分及工艺参数作为15-5PH沉淀硬化不锈钢工程化的基准,为该钢的工业化生产的顺利实施提供可靠的数据。

There trial heats of 15-5PH stainless steel in different carbon contents melting by vacuum induction furnace were secured,and by using thermal simulation,best rolling temperature range of 900~1100℃ has been gained.The effect of carbon content on transformation temperature and mechanical properties of the steel was studied,and the microstructure of aging were observed.The results showed that,the transformation temperature decreasing with the increasing of carbon content,after aging treatment,the strength of #1 steel was higher than the strength of #2 and #3 steel,and #1 steel also has better ductile plastic;Compare to #1 steel,the formation speed of reverted austenite is faster and amount is more in #2 and #3 steel with aging temperature increasing,this is main reason of the lower strength of #2 and #3 steel.After aging,the microstructure of 15-5PH steel is lath martensite and a few reverted austenite,with large amount of fine precipitates rich in copper,the Cu-rich precipitates are major enhancement patterns of the steel.So we recommend the chemical composition and technical parameters of #1 steel as engineering goal of 15-5PH steel,and provides some data for reference in the industrial production of the steel in the near future.