加热温度对X80M管线钢性能和组织的影响  

Effect of heating temperature on the mechanical properties and microstructures of X80M pipeline steels

作　　者：徐海健 韩楚菲 郭诚 龙山[1] 田永久 沙孝春[1] Xu Haijian;Han Chufei;Guo Cheng;Long Shan;Tian Yongjiu;Sha Xiaochun(Anshan Iron&Steel Co.,Ltd.,Anshan 114009,Liaoning,China;Anshan Iron&Steel Construction Co.,Ltd.,Anshan 114009,Liaoning,China)

机构地区：[1]鞍钢股份有限公司,辽宁鞍山114009 [2]鞍钢建设集团有限公司,辽宁鞍山114009

出　　处：《钢铁钒钛》2024年第1期139-144,共6页Iron Steel Vanadium Titanium

摘　　要：研究了不同加热温度对厚壁X80M管线钢原始奥氏体晶粒、组织、析出相及力学性能的影响。结果表明,加热温度对厚规格X80M管线钢的落锤性能影响较大。随着加热温度逐渐升高,奥氏体晶粒不断粗化,当加热温度≤1 210℃时,原始奥氏体晶粒细小,奥氏体晶粒的平均尺寸为35μm。原始奥氏体晶粒越细小,在后续轧制和冷却过程中越能促进针状铁素体和粒状贝氏体的形核,即显著改善钢板的低温韧性。此外,加热温度越高,铸坯中合金元素的固溶量越多,能促进20 nm以下的NbC析出相的形成,但会导致晶粒粗化和组织中针状铁素体及粒状贝氏体比例减少。因此,控制加热温度在1 210℃以下,保证针状铁素体(AF)和粒状贝氏体(GB)比例在60%以上时,可显著改善厚规格X80M管线钢的落锤性能。The effects of heating temperatures on the prior austenite grain size,microstructure and mechanical properties of X80M pipeline steels with a large wall thickness were investigated in this paper.The results showed that the heating temperature has a great effect on the drop weight tear test(DWTT)properties of X80M pipeline steels.The austenite grains continued to coarsen with enhancing the heating temperatures.The average austenite grain size was within 35μm by controlling the heating temperature below 1210℃.The finer prior austenite grains provide more nucleation sites of acicular ferrite(AF)and granular bainite(GB),and improve the low temperature toughness of steel plates during the subsequent rolling and cooling processes.Moreover,the higher solution degree of alloy elements in the casting blank promotes the formation of finer NbC precipitates with the sizes less than 20 nm by increasing heating temperature.It also leads to the grain coarsening and the decrease of AF and GB proportions in the microstructure.Therefore,the DWTT properties of X80M pipeline steels with the large wall thickness can obviously be improved by controlling the heating temperatures below 1210℃and ensuring the acicular ferrite(AF)and granular bainite(GB)phase contents more than 60%.

关 键 词：X80M管线钢 加热温度 落锤性能 针状铁素体 粒状贝氏体 

分 类 号：TF76[冶金工程—钢铁冶金] TG142.1[一般工业技术—材料科学与工程]