A Simple Test for Solidification Cracking Susceptibility and Filler Metal Effect

作者：Soysal T; Kou S^*

来源：Welding Journal, 2017, 96(10): 389S-401S.

• Solidification Cracking
• Varestraint Test
• Mushy Zone
• Deformation Rate
• Aluminum Alloys
• Gas Metal Arc Welding (GMAW)
• Filler Metals

Solidification cracking is a serious weld defect, and it is essential to test the susceptibility to this defect. In Varestraint testing, the workpiece is bent suddenly during welding to induce cracking. This causes an unrealistically high deformation rate, and the global deformation rate of the workpiece cannot reveal the local deformation rate of the mushy zone that causes cracking. A simple new test was developed in the present study, where two pieces of materials were welded, while one piece moves normal to the welding direction at the speed V. V is the lateral tensile deformation rate of the mushy zone that causes solidification cracking. As V was increased from zero, the transition from no crack propagation to full crack propagation occurred over a range of V, called the transition range. The crack susceptibility is lower if the transition range is located at a higher V level because a faster deformation rate V is required to cause crack propagation. It was shown that the V level of the transition range increased, i.e., the crack susceptibility decreased, in the order of 6061 AI, 7075 Al, 2024 Al, 2014 Al, and 2219 Al, consistent with reported data. The crack susceptibility decreased when 6061 Al and 7075 Al were welded with filler 4043 Al, and 2014 Al and 2024 Al with filler 4145 Al. This is consistent with published filler metal guides and data. The repeatability of the present test and its several significant advantages over the Varestraint test, including the use of a filler metal, were discussed. Because the Varestraint test has long been the most widely used test for solidification cracking, the present test is particularly significant.

• 出版日期2017-10