微合金钢焊缝金属中针状铁素体相变动力学分析

Dynamics of AF transformation in weld metal of microalloyed steels

采用热膨胀法成功地测出不同热输入下微合金钢焊缝金属组织中针状铁素体(AF)相变开始温度及终止温度,并绘制出AF转变开始温度和终止温度曲线,得出焊缝金属组织中AF相变温度范围为668～541℃.在热模拟和定量金相试验基础上,通过对试验数据的分析,建立了微合金钢焊缝金属中AF相变的各种T-tc-f动力学曲线.通过对AF各种相变动力学曲线的分析和讨论,得出微合金钢焊缝金属组织中AF相变的一般规律.

The starting and finishing temperature of Acicular Ferrite (AF) in weld metal of microalloyed steels for different heat-input have been measured by using the thermal-expanding method. The curves of transformation have also been plotted. The temperature range of AF transformation is between 668°C and 541°C. The T-tc-f dynamics curves of AF transformation have been established based on the thermal simulating data and quantitative microstructure tests. The common rules of AF transformation in weld metal of microalloyed steels have been obtained by analyzing the dynamics curves.