南钢超快冷工艺技术生产X70管线钢的组织性能研究

通过扫描电子显微镜(SEM)、电子背散射衍射系统(EBSD)和透射电子显微镜(TEM)等方法,针对基于超快速冷却技术(UFC)、减量化成分及工艺设计生产的X70管线钢进行组织和性能分析研究,结果表明:试制X70管线钢的组织为典型针状铁素体,组织尺寸细小均匀,交错排列,达到了细晶强化和韧化的效果;强度、塑性、冲击韧性和厚度方向组织均匀性均好于应用传统层流冷却工艺获得的各项性能;屈服强度、抗拉强度、延伸率和冲击值等各项性能都符合质量标准,且性能稳定。以超快速冷却技术为核心的新一代TMCP工艺具有良好的应用前景。

Research on Microstructure and Mechanical Properties of X70 Pipeline Steel Produced by Ultra-fast Cooling Technique

By means of SEM,EBSD and TEM,the paper performs analysis and study on the microstructure and mechanical properties of X70 pipeline steel produced by Ultra-fast cooling technique,reduced chemical composition and process design.The results show that the produced X70 pipeline steel composes of typical accicular ferrite with refined,uniform and staggerred microstructure,achieving refined grain strengthening and toughening results.The strength, plasticity,impact toughness and through thickness microstructure homogeneity are superior over those attained by laminar flow cooling process,all the indicators such as yield strength,tensile strength,elongation and impact values are stable and conform to the quality standard.The new generation TMCP process with ultra-fast cooling technique as the core technology is of bright future of application.