论文部分内容阅读
利用彩色金相、扫描电镜及拉伸实验等方法,研究了I&Q&PB热处理工艺下低碳硅锰钢在450℃时不同等温时间淬火碳配分工艺对其组织及力学性能影响。结果表明,经不同时间等温碳配分工艺处理,实验钢显微组织基本由粒状贝氏体及粒状组织构成。当配分时间在200~600s时,晶界边缘大块状M/A岛数量逐渐减少,但细小颗粒状M/A岛数量逐渐增多并趋于有序化排列,导致抗拉强度升高,伸长率降低。随碳配分时间延长,细小颗粒状M/A岛又趋于弥散化排列,并且当碳配分时间大于1 200s时出现无碳化物板条贝氏体,其贝氏体板条间的薄膜状残余奥氏体更加稳定,同时受弥散排列的细小颗粒状M/A岛影响,伸长率得到提高,抗拉强度减少。
The effects of different carbonization process on the microstructure and mechanical properties of low carbon silicon manganese steel with different isothermal time at 450 ℃ were studied by means of color metallography, scanning electron microscopy and tensile test. The results showed that the microstructure of the experimental steel consisted mainly of granular bainite and granular structure after being treated with the isothermal carbon partitioning process at different times. When the partitioning time is between 200 and 600 s, the number of M / A islands at the edge of the grain boundary gradually decreases, but the number of fine granular M / A islands gradually increases and tends to be ordered, resulting in an increase in tensile strength and elongation The rate of decrease. With the extension of carbon partitioning time, fine granular M / A islands tended to diffuse and arranged, and when the carbon partitioning time was more than 1 200s, there appeared carbide-free lath bainite and its film-like remnant between bainite laths Austenite is more stable, while being affected by fine granular M / A islands dispersedly arranged, the elongation is improved and the tensile strength is reduced.