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
徐海健 1韩楚菲 1郭诚 2龙山 1田永久 1沙孝春1
作者信息
- 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
- 折叠
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35 μm.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.
Abstract
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 pa-per.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 35 μm by controlling the heating temperature below 1 210 ℃.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 dur-ing the subsequent rolling and cooling processes.Moreover,the higher solution degree of alloy ele-ments 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 1 210 C 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Key words
X80M pipeline steel/heating temperature/drop weight tear test properties/acicular ferrite/granular bainite引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据