论文部分内容阅读
利用Gleeble热模拟试验、碳氮化物萃取试验,并结合TEM、EDS与XRD等分析方法,研究了稳定化元素铌钛对两种430铁素体不锈钢第二相高温析出行为的影响。结果表明,常温下SUS 430不锈钢基体上含有大量Cr23C6,起到一定的析出强化作用。由于该析出物的溶解温度在950℃左右,高温(950℃)下大部分融入基体,残留Cr23C6主要在晶界呈链状析出。高温强化机制主要是固溶强化。铌钛双稳定430不锈钢(NTS430)中,Cr23C6型析出物被(Ti,Nb)C取代,主要析出相为Ti N和(Ti,Nb)C,在晶粒内部含有少量的Fe2Nb,且主要析出温度均高于1200℃,因此在常温与高温(950℃)下析出相的数量和类型变化不大,保持了较好的组织稳定性和析出强化效果。
The influence of the stabilization element niobium and titanium on the high temperature precipitation behavior of the second phase of the two ferritic 430 ferritic stainless steels was investigated by Gleeble thermal simulation and carbonitride extraction and TEM, EDS and XRD analysis. The results show that the SUS 430 stainless steel substrate contains a large amount of Cr23C6 at room temperature, which has some precipitation strengthening effect. Since the dissolution temperature of the precipitate is about 950 ° C, most of the precipitate is incorporated into the matrix at a high temperature (950 ° C), and residual Cr23C6 mainly precipitates in a chain at the grain boundary. High temperature strengthening mechanism is mainly solid solution strengthening. In the niobium-titanium bismuth-stabilized 430 stainless steel (NTS430), the Cr23C6-type precipitates are replaced by (Ti, Nb) C and the major precipitates are TiN and (Ti, Nb) C with a small amount of Fe2Nb inside the grains, The temperature is higher than 1200 ℃, so at room temperature and high temperature (950 ℃) the number and type of precipitates changed little, maintaining good stability and precipitation strengthening effect.