显微组织对薄壁X65M管线钢落锤试验性能的影响  

Influence of Microstructure on DWTT Performance of Thin-wall X65M Pipeline Steel

作　　者：张明 Zhang Ming(Special Steel Research Institute,Jiangyin Xingcheng Special Steel Works Co.,Ltd.,Jiangyin 214429,China)

机构地区：[1]江阴兴澄特种钢铁有限公司特钢研究院,江阴214429

出　　处：《特殊钢》2024年第5期123-126,共4页Special Steel

摘　　要：对厚度为6~9.5 mm的薄壁管线钢低温落锤性能容易出现波动的问题,通过轧制对比实验分析,探究了薄规格X65M管线钢低温落锤性能的控制工艺的影响因素。通过不同低温落锤试验结果样品的显微组织分析和数值化结构研究,发现钢中多边形铁素体晶粒尺寸大小和钢板心部片条状分布的M/A组织对低温落锤性能影响显著。当钢中面积在200μm^(2)以上的晶粒数量较多,平均面积超过260μm^(2),或者M/A组织占比>6%时,钢板低温落锤性能明显恶化。通过连铸过热度控制以及控轧控冷工艺优化,有效细化了晶粒尺寸并减少了M/A组织的形成,实现6~9.5 mm薄壁钢板批量稳定生产8万t以上,可以满足-30℃低温落锤要求,对薄规格管线钢产品的研发和生产具有重要意义。The paper addresses the issue of fluctuating low-temperature drop-weight tear test(DWTT)performance in 6-8 mm thin-wall pipeline steel,the influencing factors of the control process of low-temperature DWTT of X65 thin-wall pipeline steel have been explored.With microstructure analysis and numerical deconstruction study of different lowtemperature DWTT results,,it reveal that the size of polygonal ferrite grains and the distribution of M/A constituents in the central part of the steel plate significantly affect low-temperature DWTT performance.When the average area of grains with an area≥200μm^(2) is greater than 260μm^(2),and the proportion of M/A constituents is greater than 6%,DWTT performance shall deteriorate significantly.By optimizing the composition and continuous casting and rolling processes,control of grain size and M/A constituents can effectively improve the low-temperature DWTT performance of thin-specification pipeline steel.The related product has achieved stable production of more than 80,000 tons,meeting the requirement of-30℃low-temperature DWTT,it is of great significance for the development and production of thin-wall pipeline steel products.

关 键 词：薄壁管线钢 落锤 晶粒尺寸 M/A组织 X65M 

分 类 号：TG142.1[一般工业技术—材料科学与工程]