环境压力与焊接极性对GMAW焊接过程稳定性的影响

发布时间：2018-01-10 15:07

本文关键词：环境压力与焊接极性对GMAW焊接过程稳定性的影响　出处：《北京化工大学》2014年硕士论文　论文类型：学位论文

【摘要】：近年来,随着我国海洋资源的不断开发,越来越多的采油平台、输油管道等水下构件需要组装和维修,水下焊接技术的重要性日益突出。由于海洋资源的开采深度不断增大,焊接环境压力不断升高,焊接环境对水下焊接技术提出了更高的要求,所以研究及发展适合深海域的水下焊接技术意义重大。高压干法GMAW被认为是当前最主要的水下焊接方法之一,与常压焊接相比,高压环境会对焊接过程的稳定性产生新的影响,但目前我国对高压干法GMAW的研究仍然处于初期阶段。本文通过高压焊接实验系统开展了焊接实验,研究了环境压力对GMAW焊接过程稳定性的影响,并通过改变焊接极性,研究了焊接极性对高压干法GMAW的影响。本文的主要研究内容如下： (1)基于高压焊接实验舱,设计了GMAW焊接实验平台和焊接控制系统,实现了高压环境密封舱条件下的自动化焊接。建立了焊接过程信息采集系统,可进行焊接过程电弧形态、熔滴过渡行为、焊接电信号等信息的采集。 (2)基于正交设计方法,设计了实验方案。根据实验要求选取了合适的焊接试件,设置了焊接参数,规划了焊接实验的基本步骤。 (3)根据实验方案进行了高压干法GMAW焊接实验,依次设定环境压力为01MPa、0.4MPa、0.7MPa、1.0MPa,采集焊接过程的相关信息,分析总结了压力对焊接过程稳定性的影响规律,如随着环境压力的升高,焊接过程的稳定性逐渐下降 (4)分别调节焊接电参数、焊丝伸出长度及保护气成分等因素进行了焊接实验,研究了这些因素对高压干法GMAW的影响情况,确定了最优的焊接参数,为相关工程应用提供了参考依据。 (5)通过对比直流反接和直流正接时的焊接过程稳定性、焊缝表面成形、焊缝截面成形情况,研究了焊接极性对高压干法GMAW的影响。本文研究表明,对于高压干法GMAW,随着环境压力的升高,焊接过程稳定性逐步下降,飞溅现象严重；在压力环境下,通过采用直流正接的方式能够明显改善飞溅现象。该研究为今后高压干法GMAW焊接的进步研究及应用奠定了基础。
[Abstract]:In recent years, with the continuous development of marine resources in China, more and more offshore platforms, pipelines and other underwater components need to assemble and repair, underwater welding technology has become increasingly prominent. The importance of marine resources due to the mining depth increasing, rising high pressure welding environment, welding environment puts forward higher requirements for water the welding technology, so the research and development for deep sea underwater welding technology is of great significance.
Hyperbaric GMAW is considered to be the most important one of the underwater welding method, compared with the conventional welding, high pressure environment will produce new effects on the stability of welding process, but the current research on hyperbaric GMAW in China is still in the early stage. Through the experimental system of high-pressure welding welding experiments are carried out on the environment, effect of pressure on GMAW welding process stability, and by changing the polarity welding, the welding effect of polarity on hyperbaric GMAW. The main contents of this paper are as follows:
(1) high pressure welding experiment module based on the design of the welding experiment platform and welding control system GMAW automation is realized under the condition of high pressure sealing welding. The welding process information acquisition system, can make the welding arc shape, droplet transfer behavior, welding electrical signal to collect information.
(2) based on the orthogonal design method, we designed the experimental scheme. According to the experimental requirements, we selected the suitable welding specimen, set the welding parameters, and planned the basic steps of the welding experiment.
(3) according to the experimental scheme of hyperbaric GMAW welding experiment, in order to set the environmental pressure of 01MPa, 0.4MPa, 0.7MPa, 1.0MPa, information acquisition of the welding process, analyzed and summarized the influence of pressure on the stability of the welding process, such as the ambient pressure increases, the stability of welding process gradually decreased
(4) the welding experiments were carried out by adjusting the welding electric parameters, the length of the welding wire and the composition of the shielding gas respectively. The influence of these factors on the high-pressure dry GMAW was studied, and the optimal welding parameters were determined, which provides a reference for related engineering applications.
(5) by comparing the stability of welding process, the forming of weld surface and the forming of weld cross section, the influence of welding polarity on high pressure dry GMAW is studied.
This study shows that for high pressure dry GMAW, with the increase of ambient pressure, the welding process stability gradually decreased, splash phenomenon is serious; under pressure, through the use of DC method can significantly improve the splash phenomenon. This study lays a foundation for future GMAW hyperbaric welding progress in research and application.

【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P755.1

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