小型压力容器MAG单面焊双面成形技术研究

发布时间：2019-04-08 17:56

【摘要】：单面焊作为一种高效的焊接技术,广泛应用于桥梁、船舶、压力容器和各种大型钢结构及设备的制造。与双面焊相比,它能够显著提高生产效率、改善工作环境、降低工人的劳动强度,提高焊接质量,具有十分显著的经济和社会效益。目前,我国尤其唐山地区,小型压力容器焊接方法主要是CO2气体保护焊,其优点为生产率高、焊接变形小、高性价比、易操作。但是CO2气体保护焊还存在许多不足,例如焊缝光滑度差、飞溅大、易产生气孔等问题,很难实现单面焊双面成形。保护气体的成分和配比直接影响电弧焊接特性,决定焊缝成形、焊接工艺稳定性及接头性能。混合气体保护焊(MAG)消除了CO2气体保护焊的诸多缺点,改善了焊缝质量,易于实现单面焊双面成形。本文针对目前小型压力容器行业焊接实际情况,从MAG单面焊双面成形基本理论入手,分析了保护气体与小型压力容器焊接工艺稳定性、焊缝成形、焊缝力学性能的关系;进行了陶瓷衬垫MAG单面焊双面成形试验研究;通过CO2气体保护焊与MAG焊的成本比较,分析了压力容器MAG单面焊双面成形工艺的现实可行性。最后应用陶瓷衬垫MAG单面焊双面成形工艺小批量生产了小型压力容器。实际应用表明,采用陶瓷衬垫富氩混合气(20%CO2+80%Ar)的焊接小型压力容器,经过工艺评定,焊缝成型美观、无咬边、气孔等缺陷,经拉伸试验、弯曲试验、冲击试验、外观及射线检测均达到使用要求。本文为小型压力容器单面焊双面成形工艺改进提供了可靠的技术保证。陶瓷衬垫富氩MAG焊用于小型压力容器的焊接加工,焊接接头综合性能优于二氧化碳气体保护焊,值得推广应用。
[Abstract]:As an efficient welding technology, one-sided welding is widely used in the manufacture of bridges, ships, pressure vessels and various large steel structures and equipment. Compared with double-sided welding, it can significantly improve the production efficiency, improve the working environment, reduce the labor intensity of workers, and improve the welding quality, which has remarkable economic and social benefits. At present, in our country, especially in Tangshan area, the main welding method of small pressure vessel is CO2 gas shielded welding, which has the advantages of high productivity, small welding deformation, high price-to-performance ratio and easy operation. However, there are still many shortcomings in CO2 gas shielded welding, such as poor smoothness of welding seam, large spatter, easy to produce porosity and so on. It is difficult to realize the double-sided forming of one-sided welding. The composition and proportion of shielded gas directly affect the characteristics of arc welding, determine the weld forming, welding process stability and joint performance. Mixed gas shielded welding (MAG) eliminates many disadvantages of CO2 gas shielded welding, improves weld quality, and is easy to realize one-sided welding and double-sided forming. According to the actual situation of welding in small pressure vessel industry, this paper analyzes the relationship between shielded gas and welding process stability, weld forming and weld mechanical properties of small pressure vessel based on the basic theory of MAG one-sided welding and double-sided forming. The two-sided forming test of ceramic liner MAG single-side welding was carried out, and the feasibility of MAG single-side welding double-sided forming process of pressure vessel was analyzed by comparing the cost of CO2 gas shielded welding and MAG welding. Finally, small pressure vessels were produced in small batches by ceramic liner MAG single-side welding and double-side forming process. The practical application shows that the welded small pressure vessel with ceramic gasket and rich argon mixture (20%CO2 80%Ar) has been evaluated by process evaluation, the weld is beautiful in shape, has no defects such as edge biting and porosity, the tensile test, bending test and impact test are carried out, and the results are as follows: 1. Appearance and X-ray detection meet the requirements of use. This paper provides a reliable technical guarantee for the improvement of single-side welding and double-side forming process of small pressure vessels. Argon-rich MAG welding with ceramic liner is better than CO _ 2 gas shielded welding in welding process of small pressure vessel, which is worth popularizing and applying.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG457.5

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