1Cr22Mn16N高氮钢激光焊接 I.焊接保护气体组成和热输入对焊缝氮含量及气孔性的影响

Laser welding of high nitrogen steel 1Cr22Mn16N Ⅰ. Influence of shielding gas composition and heat input on N-content and porosity of weld metal

利用CO2激光对1Cr22Mn16N高氮钢进行了焊接,研究了焊接热输入和保护气体组成对焊缝氮含量、气孔的影响。结果表明,在相同激光焊接热输入条件下,随着保护气体中氮含量的增加,高氮钢焊缝中的氮含量略有增加。当采用纯氩作为焊接保护气体时,焊缝氮含量随热输入的增加而减小;当保护气体中的氮比例达到一定比例时,焊缝氮含量随热输入的增加而增大。焊接热输入较小的条件下焊缝易产生气孔,较大的热输入将抑制焊缝中气孔的产生,而且保护气体中氮含量越高,焊缝中产生气孔的倾向越小。

In order to study the N-content and porosity of the weld metal of high nitrogen steel 1Cr22Mn16N, the steel was welded by CO2 laser welding, and the influence of the shielding gas composition and heat input on the N-content and porosity of the weld metal was investigated. The experimental results indicate that the N-content of the weld metal increases slightly as the nitrogen in the shielding gas containing Ar and N2 is increased under the same heat input. The N-content of the weld metal decreases with the increase of the heat input when pure Ar is used as the shielding gas, whereas that of the weld metal is improved with the increase of the heat input when enough nitrogen is added to the shielding gas. The higher the heat input, the less the porosity in the weld metal, and the more N2 in the shielding gas, the less the porosity forms.