超快冷技术生产X80级管线钢组织和性能的研究  

Research on Microstructure and Mechanical Properties of X80 Grade Pipeline Steel Produced by Ultra-fast Cooling

作　　者：赵显鹏 齐天圣 王振华 李东岳 Zhao Xianpeng;Qi Tiansheng;Wang Zhenhua;Li Dongyue(Shandong Iron and Steel Group Rizhao Co.,Ltd.)

机构地区：[1]山东钢铁集团日照有限公司

出　　处：《宽厚板》2022年第3期43-48,共6页Wide and Heavy Plate

摘　　要：针对X80级管线钢进行减量化成分以及工艺设计,生产出满足市场需求的高质量X80级管线钢。金相组织、扫描组织、透射组织分析显示,应用超快冷技术得到典型针状铁素体组织,晶粒细小均匀,交错排列,提高了细晶强化和韧化的效果;晶界处存在第二相,主要为M-A组元及少量(退化)珠光体,M-A岛尺寸细小,降低了对韧性的不利影响,提高了基体的形变强化能力;各晶粒之间存在较大的取向差,晶粒具有较高的大角晶界分布密度,显著改善了低温冲击韧性。其次,结合实验室拉伸性能、冲击韧性和厚度方向硬度分布等性能检测结果,X80级管线钢板的强度、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生产的钢板,屈服强度、抗拉强度、延伸率和冲击值等指标都符合质量标准,性能稳定,表明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。On the basis of reduced composition and process design,high quality X80 grade pipeline steel meeting market demand is produced.The analysis of metallographic microstructure,SEM microstructure and TEM microstructure shows that typical accicular ferrite with uniform fine grain and staggered arrangement is gained by applying ultra-fast cooling technique,which improves the effects of fine grain strengthening and toughening.Second phase existed at the grain boundary mainly consists of M/A constituent and little degraded pearlite with small sized M/A island,which reduces the adverse effects on toughness and improves the deformation strengthening ability of the matrix.Larger misorientation exists between grains with high distribution density of large angle grain boundary,which significantly improves the low temperature impact toughness.According to the mechanical properties testing results of tensile properties,impact toughness and through-thickness hardness distribution,the strength,plasticity,impact toughness and through-thickness microstructure homogeneity of X80 grade pipeline steel plate are better than those of steel plate produced by traditional lammellar cooling process with indicators of yield strength,tensile strength,elongation ratio and impact energy value satisfying the quality standard and stable properties,which shows a good application prospect of the new generation TMCP technique with ultra-fast cooling as the core technology.

关 键 词：X80级管线钢 超快冷 新一代TMCP工艺 组织分析 性能检测 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TE973[金属学及工艺—金属材料]