焊接工艺参数对超窄间隙焊接热裂纹的影响

超窄间隙焊接中热裂纹是一种很容易出现的缺陷，采用焊剂带约束电弧超窄间隙焊接试验，通过改变焊接工艺参数和间隙宽度，研究其对热裂纹的影响.结果表明，焊缝成形系数与热输入和焊缝成形系数与间隙宽度的匹配关系是决定热裂纹的主要因素.在较小的焊缝成形系数和较大的热输入量下热裂纹倾向较大，并且随着间隙宽度的减小，焊缝中热裂纹倾向明显增加.当焊缝成形系数增大到临界值时焊缝中不产生热裂纹，且临界值随热输入量的增大而逐渐增大，随间隙宽度的增大而逐渐减小.

Effects of welding parameters on ultra-narrow gap welding hot cracking

Hot cracking is a defect appearing easily In ultra-narrow gap welding. By using ultra-narrow gap welding with flux strips constrainting arc test, the effects of welding parameters and gap width on the hot cracking were studied. The result showed that the relationship between aspect factor of weld with heat input and that with gap width are the main factors to determine the hot cracking. At smaller aspect factor of weld and larger heat input, the tendency of hot cracking is larger, and with the decrease of the gap width, the hot cracking tendency significantly increase. When the aspect factor of weld increase to a critical value, the welding hot cracking will not occurred, and the critical value is gradually increased with the increase of heat input, while gradually decreased with the increase of the gap width.