含Nb微合金化Q345厚钢板组织结构及性能研究  

Study on microstructure and properties of Nb microalloyed Q345 thick steel plate

作　　者：段莉蕾 DUAN Lilei(CFHI Dalian Nuclear Power Petrochemical Co.,Ltd.,Dalian 116113,China)

机构地区：[1]一重集团大连核电石化有限公司,辽宁大连116113

出　　处：《压力容器》2023年第8期22-27,共6页Pressure Vessel Technology

摘　　要：研究了含Nb微合金化Q345厚钢板的组织结构、强度和低温冲击韧性。结果表明,Nb微合金元素的加入配合轧后加速冷却,提高了钢的淬透性,细化了晶粒,改变了钢的组织状态,在强度显著提高的同时保持了良好的低温冲击韧性。由于表面和心部冷却条件的差异性,表面形成了板条贝氏体为主的中温组织;心部形成了铁素体+索氏体的高温组织。从钢板表面到心部,强度呈下降趋势;低温冲击韧性呈上升趋势。The microstructure,strength and low temperature impact toughness of Nb microalloyed Q345 thick steel plates were studied.The results show that the addition of Nb microalloyed elements and accelerated cooling after rolling improved the hardenability of steel,refined the grains,changed the microstructure of the steel,and maintained good low temperature impact toughness while significantly increasing the strength.Due to the difference of cooling conditions in surface and core,a medium-temperature microstructure dominated by lath bainite was formed on the surface while a high-temperature microstructure of ferrite+sorstenite was formed in the core.From the surface to the core of the steel plate,the strength decreased and the low temperature impact toughness increased.

关 键 词：含Nb微合金化Q345钢 厚钢板 冷却速度 组织结构 力学性能 

分 类 号：TH142[一般工业技术—材料科学与工程] TG115.5[机械工程—机械制造及自动化]