X80和X90管线钢热影响区组织与韧性对比

摘要

In this article, the microstructure and properties of different zones of X80 and X90 pipeline steel HAZ were studied by using thermal simulation, the result indicated that the microstructure and properties of two kinds of pipeline steel in different regions are with similarities, also with some differences. In the four regions (coarse grained region, fine grained region, critical zone, subcritical zone) of the heat affected zone, the similarities are that toughness are both better in two regions (subcritical zone, fine-grained region), but the toughness in coarse grained region and critical zone both are poor; The differences are reflected in the toughness in fine-grained region of X90 steel grade is worse than that of X80 grade. After analysis, it is mainly due to in fine grained region of X90 steel, the massive ferrite with worse low temperature toughness is more than that of X80 steel.%采用热模拟方法对X80和X90管线钢进行了热影响区不同区域组织与性能的研究，研究发现：两种钢级管线钢热影响区不同区域的组织与性能既存在相同点，又有不同之处。相同点为热影响区的4个区域（粗晶区、细晶区、临界区和亚临界区）中，亚临界区和细晶区的冲击韧性较好，而粗晶区和临界区的冲击韧性较差；不同点为X90钢级管线钢热影响区细晶区韧性比X80差。经过分析认为，这主要是由于X90钢级细晶区中，低温韧性较差的块状铁素体要多于X80钢的缘故。