【作者】 王永强；

【导师】 汤文博；

【作者基本信息】 郑州大学 ， 材料加工工程， 2012， 硕士

【摘要】 不锈钢真空保温器皿生产中普遍次品率过高。本文通过检测一批样品,并分析其生产过程,确定了焊接缺陷最易出现的部位,设计出一套焊接夹具,并优化了焊接工艺参数,提高了焊接质量。采用压缩空气泄漏检测法测试一批保温杯样品,结果表明漏气部位主要分布在保温杯底部端焊焊缝位置和尾部铜管封口位置,底部端焊焊缝出现的焊接缺陷主要是焊瘤、烧穿和未熔合,原因是焊接时的对中偏差过大以及所使用的焊接工艺参数不够适合。机械化焊接时的对中偏差主要是存在同轴度偏差、端跳偏差以及保温杯的圆度偏差。采用自动调整及柔性连接的方案设计出一套自动TIG焊焊接夹具,通过保温杯位置的自动调整,对中偏差控制在0.2mm之内。焊接夹具的适用性、稳定性较好,成本较低。通过焊接工艺参数的优化试验,确定了使用焊接夹具时合适的焊接电流为20-22A,焊接速度为550-600mm/min。在使用焊接夹具及合适的焊接工艺参数条件下,所得焊缝外观平整光滑,熔深均匀,没有明显的焊接缺陷,焊缝致密,组织为细小的奥氏体和少量铁素体,试验条件下焊缝合格率接近100%更多还原

【Abstract】 Production of stainless steel vacuum vessels generally encountered high rate of product defects. This paper tested a number of samples, analyzed their production process, and determined the location of welding defects, a welding fixture was designed, welding parameters were adjusted, the quality of welding was improvedA number of insulation cup samples were tested by leak detection with compressed air, the results showed that the leak site mostly distributed in the edge weld seam position and sealing position of the tail brass at the bottom of the insulation cup, the main welding defects were weld beading, burning through and incomplete fusion, the main causes of welding defects are welding alignment deviation and the unsuitable welding parameters in welding process.The main causes of weld misalignment for mechanized welding process, are coaxial deviation, end jump and roundness deviation of the cups; an automatic TIG welding fixture was designed fixed program of automatic adjustment and flexible connection, the position of the insulation cup can be automatically adjusted, welding alignment deviation can be controlled within0.2mm; the applicability, stability and manufacturing cost control of the fixture achieved the expected goals.Welding parameters were optimized by experiment, the optimal welding current is20-22A, and the optimal welding speed is550-600mm/min for the welding with the welding fixture.With the welding fixture and suitable welding parameters, high quality weld can be obtained, the appearance of the weld was smooth, the melting depth was uniform, there were no obvious welding defects, the weld is compact and the weld microstructure is small austenite and a small amount of ferrite, qualified rate of the weld ban be close to100%in experimental conditions更多还原