奥氏体不锈钢焊缝热裂敏感性研究

应用变形速率连续可变式热裂纹试验方法（ＶＤＲ法）研究了碳、钼和稀土元素对奥氏体不锈钢焊缝热裂敏感性的影响。试验结果表明，降低奥氏体不锈钢熔敷金属中的碳含量并加入适量的钼可显著提高焊缝的抗热裂性能。稀土元素对焊缝的抗热裂性也有显著影响，加入适量稀土能减少焊缝中夹杂物的数量和大小，改变其成分及分布，提高抗裂性。但是如果加入过量，焊缝中会形成大量稀土夹杂物，降低奥氏体不锈钢焊缝的抗裂性。

HOT CRACKING SUSCEPTIBILITY IN AUSTENITIC STAINLESS STEEL WELDS

The effect of carbon, molybdenum and rare earths on hot cracking susceptibility of austenitic stainless steel welds was studied with continuously variable deformation rate cracking test (VDR) method. The test results show that the hot cracking resistance increases substaintially with the decrease of carbon content. Molybdenum and rare earths also have considerable effects. The optimum content of them can improve hot cracking resistance of welds. Based on the results of SEM and EDX, adding a suitable amount of rare earths can reduce the content and size of inclusions, change the chemical composition and distribution of inclusions in weld metal, and improve the hot cracking resistance. When rare earths content in electrode coatings is higher than 2%, a lot of slag inclusions will be formed in weld, which can reduce the hot cracking susceptibility.