80Mn14钢高温性能的研究

Research on High Temperature Performance of 80Mn14 Steel

80Mn14(0.77C、13.98Mn、0.43Si、0.050P、0.022S、0.15Cu)高锰钢的热轧工艺性能差,是凿岩中空钢用芯棒的生产和使用中遇到的主要技术问题。利用热模拟试验机测量80Mn14钢材的热塑性和抗拉强度,采用扫描电镜分析磷等元素的成分分布;利用激光共聚焦显微镜观察金相组织和晶粒度。结果表明,80Mn14钢在1215℃时的热塑性为零、晶界明显烧损;1100℃时晶粒度8级,在1200℃时晶粒严重粗化,晶粒度5级;在晶界烧损的样品中发现了明显磷偏析。因此,在1215℃以上或附近,用铸钢坯(锭)轧制80Mn14钢材不合适宜;磷的偏析是80Mn14高锰钢可轧性差的主要原因。

The poor hot rolling performance of 80Mn14（0.77C,13.98Mn,0.43Si,0.050P,0.022S and 0.15Cu） high manganese steel is the main technical problem of core bar used for rock drilling hollow steel production.The thermo-plasticity and tensile strength of 80Mn14 steel were measured by thermal simulation testing machine.The composition distributions in the grain boundary were analyzed by SEM and EDS.The microstructure was observed by laser confocal microscope and the grain size was evaluated.The results show that the thermo-plasticity of 80Mn14 at 1215 ℃ is zero and the grain boundary is burned out obviously.The grade of grain size is 8 at 1100 ℃.But the grain became coarse seriously at 1200 ℃,with grain size’s grade 5.Therefore,it is unsuitable to roll 80Mn14 by casting billet（ingot） above 1215 ℃ or around;the phosphorous segregation is the main reason for poor rolling ability of 80Mn14 high manganese steel.