焊接热循环对钛微合金中第二相粒子的影响

利用萃取复型及金属薄膜电子显微技术对Ｔｉ微合金风及其热影响区中的第二相粒子进行了分析。结果表明，含Ｔｉ微合金钢及其热影响区中主要为ＴｉＮ，此外还有少量ＡｌＮ等。经热循环后，粒子的尺寸明显增大、数量减少。与Ｔｉ，Ｎ一比（Ｔｉ／Ｎ）较高的钢相比，Ｔｉ／Ｎ较低的钢中ＴｉＮ粒子数量较多尺寸较小，且热循环过程中ＴｉＮ粒子的溶解及粗化程度减小，对原始奥氏体晶粒长大的阻碍作用较大。

INFLUENCE OF WELDING THERMAL CYCLE ON SECOND PHASE PARTICLE IN Ti MICROALLOYED STEEL

By using carbon extraction replica and metal filmTEM technique, the particles in Ti microalloyed steels and their simulated CGHAZ are investigated. Experiment results and analysis show that the majority of particles in the steels and their simulated CGHAZ are TiN particles, and a few AlN particles also exist. After simulated weld cycle, the mean particle size increases and the number per unit area decreases. Compared with the steel with high Ti/N, more particles exist in the steel with low Ti/N, the particle dissolving and coarsening rate of steel with low Ti/N is smaller, and the pinning effect on the austenite grain growth in the steel with low Ti/N is more remarkable.