保护气体对高氮钢焊接熔滴过渡模式和气孔缺陷的影响研究

发布时间：2018-08-26 21:22

【摘要】：采用激光-电弧复合热源对8 mm厚的高氮钢板进行焊接试验,研究不同保护气体组成对焊缝形貌、熔滴过渡特征和气孔缺陷的影响。结果表明,采用纯氩做保护气体时,熔滴过渡模式以射流过渡为主,并伴有少量排斥过渡;保护气体成分为Ar+N_2混合气体时,熔滴过渡模式为短路过渡;保护气体成分为Ar+N_2+O_2混合气体时,熔滴过渡模式为射流过渡。保护气体的组成对焊缝气孔缺陷也存在一定的影响,保护气体为纯氩时,焊缝气孔率最大,其值为2.52%;保护气体为90%Ar+10%N_2时,气孔率最低,仅为0.16%;Ar+N_2中添加1%的O_2后,气孔率略有升高,但与纯氩时相比,气孔率仍下降明显。采用Ar+N_2+O_2三元混合气作为保护气体时,能够有效抑制焊缝内气孔数量,同时可以改善熔滴过渡模式,提高焊接过程稳定性。
[Abstract]:The laser arc composite heat source was used to weld the 8 mm thick high nitrogen steel plate. The effects of different composition of protective gases on the weld morphology, droplet transfer characteristics and porosity defects were studied. The results show that when pure argon is used as the protective gas, the droplet transfer mode is mainly jet transfer with a small amount of repulsive transition, and the droplet transfer mode is short circuit transition when the protective gas is Ar N _ 2 mixture gas. The droplet transfer mode is jet transition when the gas component is Ar N _ 2O _ 2 mixed gas. The composition of shielded gas has a certain effect on weld porosity. When the shielded gas is pure argon, the gas porosity of weld is the largest with a value of 2.52. When the protective gas is 90%Ar 10%N_2, the porosity is the lowest, which is only 0.16% after adding 1% O _ 2 in ar _ N2. The porosity increased slightly, but still decreased significantly compared with pure argon. When the Ar N2O 2 ternary mixture is used as the protective gas, the number of gas holes in the weld can be effectively suppressed, the droplet transfer mode can be improved, and the welding process stability can be improved.
【作者单位】：长春理工大学机电工程学院;北华大学汽车与建筑工程学院;长春理工大学激光加工吉林省高等学校工程研究中心;长春理工大学国家国际科技合作基地(光学);
【分类号】：TG457.11

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