智能型抗震耐火钢Q420FRE焊接热影响区组织性能研究  

Microstructure and properties of heat- affected zone for smart anti- seismic fire- resistant steel Q420FRE

作　　者：吴年春 李丽 任晓辉[2] 覃展鹏 许可[2] 王红鸿[2] 吴开明[2] 

机构地区：[1]南京钢铁股份有限公司研究院,210035 [2]武汉科技大学,430081

出　　处：《焊接》2014年第8期60-64,4,共5页Welding & Joining

摘　　要：采用Gleeble3800热模拟试验机对智能型抗震耐火钢Q420FRE焊接热影响区组织转变行为进行了研究.结果表明,在不同的焊接热循环条件下,Q420FRE焊接热影响区的组织均以粒状贝氏体为主,硬度变化不大,硬度平均值为HV0.2 185 ～ 207.随着冷却速度的减小,贝氏体铁素体板条宽度略有增加,从2.38μm增大到3.28 μm;M-A组元含量先增大到2.32％,之后逐渐减少到0.80％;M-A组元尺寸变化不大,当t8/5＜ 30 s时,约为1.25 ～ 1.28 μm;当t8/5＞ 50 s时,约为1.00 ～ 1.05 μm.焊接热影响区组织的稳定性决定了智能型微合金化Q420FRE耐火钢具有优良的焊接性,可适用于大热输入量焊接.The microstructure evolution of heat- affected zone for smart anti- seismic fire- resistant steel Q420 FRF was investigated using Gleeble 3800.The microstructure of heat- affected zone of Q420 FRE was predominantly granular bainite under the different welding thermal cycles.However,the hardness changed a little,whose average value HVO.2 was about 185-207.As the cooling rate being decreased,the banitic ferrite lath increases slightly from 2.38 μm to 3.28 μm,the content of martensite- austenite constituents increase to 2.32% firstly and then decrease to 0.80%gradually,the size of martensite- austenite constituents do not vary significantly,which is about 1.25~1.28 μm when the cooling time of t8/5 is less than 30 s,and 1.00~1.05 μm when t8/5 is greater than 50 s.The microstructure stability of heat- affected zone leads to the perfect weldability of smart anti- seismic fire- resistant steel Q420 FRF.This result confirms that the Q420 FRF steel can be welded with higher heat input.

关 键 词：耐火钢 微合金化 热影响区 组织转变 M-A 

分 类 号：TG406[金属学及工艺—焊接]