微合金钢焊接粗晶区晶粒长大的热模拟研究

Thermal Simulated Research on the—Grain Growth in Welding Coarse Grained Zone of Microalloyed Steel

采用焊接热模拟方法，研究了不同的焊接热循环参数Ｔｍａｘ和ｔｍａｘ／８对Ｔｉ、Ｎｂ和Ｎ复合加入的两种成分系更的微合金钢昌区奥氏体晶粒尺寸长大的影响。结果表明，奥氏体晶粒尺寸随Ｔｍａｘ增大而增大；并且Ｔｍａｘ恒定时，随着时间延长，长大倾向不岑ｉ低的Ｔｉ－Ｎｂ－Ｎ钢的（ＢＢ５０３）长大倾向严重。ｔｍａｘ／８增大时，两种成分系列钢奥氏体晶粒尺寸变化平缓，但含Ｔｉ低的Ｔｉ－Ｎ钢（１＾＃）和Ｔｉ－Ｎｂ－Ｎ钢（

By means of the simulated weld thermal cycling ,the effect of the process parameters T_(max) and t_(max/8) has been studied on the austenite grain growth in coarse-grained zone of the two series of microalloyed steels additivated with Ti,Nb and N.It was found that the austenite grain size increased with rising T_(max);and when T_(max) was constant,the growing trends of austenite grain of different steels were distinct with the extension of incubation time,the austiente grain of Ti-Nb-N steel(BBS03) with low Ti content coarsened distinctly.When t_(max/8) increased, austenite grain size of the two series of steels increased slightly,and that of Ti-N steel(1~#) and Ti-Nb-N steel(4~# BBS03)with low Ti content increased significant- ly.