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由于在焊接接头和焊肉中形成脆性组织,要恢复替换下来的冶金设备铸件的质量是困难的。用钢焊条焊接和堆焊时,由于母材中碳的扩散,会出现焊肉渗碳现象。堆焊层中的碳含量分布不一致:表面0.2—0.3%,过渡带上为2.8—3.0％。因此、焊肉的机械物理性能在焊波截面上也不尽一致,这就会导致形成裂纹。由于母材中含有大量的碳,因此,在焊接和堆焊时会出现大量的气体。在焊肉的快速冷却情况下,这种气体也来不及消失,而得到的是疏
Due to the formation of brittle tissue in welded joints and welding meat, it is difficult to restore the quality of the replaced metallurgical equipment castings. Welding and welding with steel welding rod, due to the diffusion of carbon in the parent material, there will be welding carburizing phenomenon. The carbon content in the surfacing layer is not uniform: 0.2-0.3% of the surface and 2.8-3.0% of the transition zone. Therefore, the mechanical properties of welding meat in the welding wave cross-section are not the same, which will lead to the formation of cracks. Due to the large amount of carbon contained in the base metal, a large amount of gas appears during welding and surfacing. In the case of rapid cooling of the welding meat, this gas is also too late to disappear, and get sparse