Al-Mg合金横焊气孔敏感性研究
发布时间：2019-05-12 11:44
【摘要】：针对目前大型气垫登陆艇1561高强度铝合金及配套焊材熔化极惰性气体保护焊MIG横焊气孔率高、接头软化程度大、工艺不过关等问题,开展MIG横焊技术的工艺适应性研究。研究MIG横焊位置的气孔敏感性,分析气孔形成原因,探索焊缝中气孔的控制措施,与此同时,研究MIG横焊焊缝气孔敏感性与力学性能之间的关系,优化焊接工艺,以获得良好的组织与力学性能。首先从基材内部原因即基材氢含量角度进行试验,为研究基材氢含量对横焊气孔敏感性的影响,分别对1561、5083铝镁合金以及1561、ER5183铝合金焊丝进行氢含量测定,使用美国力可公司RHEN602氢分析仪,利用脉冲加热-石墨电极炉-热导法进行检测,根据检测结果进行试验,试验结果表明高氢含量的母材与焊丝对气孔敏感性的影响显著,并且焊丝的影响程度要大于母材的影响程度。对基材进行高温预热去氢,试图降低基材表面氢含量,试验结果表明在预热炉300℃下预热5h后随炉冷却的基材横焊气孔敏感性明显降低。然后从外部原因即焊前清理、焊枪角度、保护气体种类及成分、焊接电流、焊接电压、焊接速度等角度进行控制变量试验,焊前清理分为基材的机械清理和化学清理,在基材的机械清理的基础上进行化学清理可以明显降低气孔敏感性;焊枪角度分为上倾5°、水平、下倾5°,焊枪角度上倾5°的焊缝气孔敏感性最低;保护气体种类分为纯氩气和氩气与氦气的混合气,25%氦气+75%氩气的气孔敏感性最低;焊接电流分为103A、108A、113A,随着焊接电流的增加,焊缝气孔敏感性明显增加;焊接电压分为18V、21V、24V,随着焊接电压的增加,焊缝气孔敏感性逐渐减少;焊接速度分为350mm/min、450mm/min、550mm/min,随着焊接速度的增加,焊缝气孔敏感性逐渐减少。最后对焊接工艺进行优化,试图得到气孔敏感性最低的焊缝,在上述焊前清理、焊枪角度、保护气体等最优焊接条件情况下,摸索最优的焊接参数,对焊接电流、焊接电压、焊接速度三个因素进行正交试验,试验结果表明焊接电压对气孔敏感性的影响程度最大,最优的焊接参数为:焊接电流108A,焊接电压24V,焊接速度450mm/min,并发现此焊接工艺参数下的焊缝力学性能最好。为了进一步降低气孔敏感性,利用涂抹活化剂进行焊接,试验结果表明活化剂可以有效地降低气孔的敏感性,并明显提高了焊缝的拉伸强度。
[Abstract]:In order to solve the problems of large air cushion landing boat 1561 high strength aluminum alloy and matching welding material melting pole inertia gas shielded welding MIG transverse welding, the process adaptability of MIG transverse welding technology is studied in view of the problems such as high porosity, high soften degree of joint and failure of process. The porosity sensitivity of MIG transverse welding position is studied, the causes of porosity formation are analyzed, and the control measures of porosity in weld are explored. At the same time, the relationship between porosity sensitivity and mechanical properties of MIG transverse welding seam is studied, and the welding process is optimized. In order to obtain good microstructure and mechanical properties. Firstly, the hydrogen content of 1561, 5083 Al-mg alloy and 1561, ER5183 aluminum alloy welding wire was determined in order to study the effect of substrate hydrogen content on porosity sensitivity of transverse welding. The RHEN602 hydrogen analyzer of American Like Company was used to detect the stomatal sensitivity by pulse heating-graphite electrode furnace-thermal conductivity method. According to the test results, the test results show that the base metal and welding wire with high hydrogen content have a significant effect on stomatal sensitivity. And the influence degree of welding wire is greater than that of base metal. The substrate was preheated and dehydrogenated at high temperature in an attempt to reduce the hydrogen content on the surface of the substrate. The experimental results show that the porosity sensitivity of the substrate cooled with the furnace is obviously reduced after preheating at 300 鈩，
本文编号：2475365
[Abstract]:In order to solve the problems of large air cushion landing boat 1561 high strength aluminum alloy and matching welding material melting pole inertia gas shielded welding MIG transverse welding, the process adaptability of MIG transverse welding technology is studied in view of the problems such as high porosity, high soften degree of joint and failure of process. The porosity sensitivity of MIG transverse welding position is studied, the causes of porosity formation are analyzed, and the control measures of porosity in weld are explored. At the same time, the relationship between porosity sensitivity and mechanical properties of MIG transverse welding seam is studied, and the welding process is optimized. In order to obtain good microstructure and mechanical properties. Firstly, the hydrogen content of 1561, 5083 Al-mg alloy and 1561, ER5183 aluminum alloy welding wire was determined in order to study the effect of substrate hydrogen content on porosity sensitivity of transverse welding. The RHEN602 hydrogen analyzer of American Like Company was used to detect the stomatal sensitivity by pulse heating-graphite electrode furnace-thermal conductivity method. According to the test results, the test results show that the base metal and welding wire with high hydrogen content have a significant effect on stomatal sensitivity. And the influence degree of welding wire is greater than that of base metal. The substrate was preheated and dehydrogenated at high temperature in an attempt to reduce the hydrogen content on the surface of the substrate. The experimental results show that the porosity sensitivity of the substrate cooled with the furnace is obviously reduced after preheating at 300 鈩，
本文编号：2475365
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