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引言焊接是接近或最接近于使用状态的工艺,对于工程材料的韧性以及工程结构的脆断,有着重要的影响。熔化焊接时,在几个毫米范围内,几秒到几分钟内发生了较为复杂的物理和化学变化,具有如下的几个重要特征:(1)包括从冶炼、铸造到热处理的全部工艺,发生了相应的变化。(2)上述变化在较大的温度梯度、加热速度和冷却速度条件下发生。(3)焊丝和基体(或母材)的化学成分一般有差异,上述变化的结果。使焊区有成分和组织结构的区别,并且还有残余应力的存在。
Introduction Welding is a process that is close to or closest to the operating condition and has an important effect on the ductility of engineering materials and the brittle fracture of the structure. In fusion welding, complex physical and chemical changes occur within a few millimeters over a few seconds to minutes, with several important features as follows: (1) Including everything from smelting, casting to heat treatment, The corresponding changes. (2) The above changes occur at larger temperature gradient, heating rate and cooling rate. (3) The chemical composition of the wire and matrix (or base metal) is generally different, as a result of the above changes. The weld zone has the difference of composition and structure, and also the existence of residual stress.