矩阵法对焊接接头硬度值分布的分析研究

Analysis study of hardness value distribution in welded joints by matrix method

为解决标线法对50 mm厚EQ47调质态钢板多层多道焊接接头维氏硬度测试的局限性,采用一种矩阵测试方法,通过对焊接接头进行详细的微区硬度测试,并根据硬度值绘制硬度等值线图,结果显示该方法可以直观显示焊接接头的硬度值分布以及各硬度值区域所占比例;同时对硬度等值线图上不同硬度值区域的显微组织和微区成分进行较深入的分析和研究。结果表明:不同位置硬度值的差别与显微组织有关,与元素的分布基本无关,该方法既能定性又能定量进行硬度值分布表征,更加有利于对焊接接头的组织及力学性能进行分析。

To avoid the limitation of Vickers hardness test on the multi-layer multi-pass welded joints of 50 mm thick EQ47 QT steel plates by marking method, this study adopts the matrix method to test the micro area hardness of welded joints in detail and draw the hardness value isogram. The results show that this method can directly show the hardness value distribution of welded joints and the proportion of each hardness value range by means of the hardness value isogram; besides, a deep analysis has been carried out on the microstructure and micro area compositions in different hardness value areas on the hardness value isogram, and the research results show that the hardness value in different locations are relevant to the microstructure,irrelevant to the element distribution. Matrix method is a comprehensive hardness testing method,which can not only characterize hardness distribution quantitatively and qualitatively, but also benefit the structure and mechanical property analysis of welded joints.