發(fā)布時間：2018-01-10 15:07

  本文關鍵詞：環(huán)境壓力與焊接極性對GMAW焊接過程穩(wěn)定性的影響　出處：《北京化工大學》2014年碩士論文　論文類型：學位論文

  更多相關文章： 高壓焊接 焊接極性 GMAW 電弧形態(tài) 熔滴過渡 焊縫成形

【摘要】：近年來,隨著我國海洋資源的不斷開發(fā),越來越多的采油平臺、輸油管道等水下構件需要組裝和維修,水下焊接技術的重要性日益突出。由于海洋資源的開采深度不斷增大,焊接環(huán)境壓力不斷升高,焊接環(huán)境對水下焊接技術提出了更高的要求,所以研究及發(fā)展適合深海域的水下焊接技術意義重大。 高壓干法GMAW被認為是當前最主要的水下焊接方法之一,與常壓焊接相比,高壓環(huán)境會對焊接過程的穩(wěn)定性產生新的影響,但目前我國對高壓干法GMAW的研究仍然處于初期階段。本文通過高壓焊接實驗系統(tǒng)開展了焊接實驗,研究了環(huán)境壓力對GMAW焊接過程穩(wěn)定性的影響,并通過改變焊接極性,研究了焊接極性對高壓干法GMAW的影響。本文的主要研究內容如下： (1)基于高壓焊接實驗艙,設計了GMAW焊接實驗平臺和焊接控制系統(tǒng),實現(xiàn)了高壓環(huán)境密封艙條件下的自動化焊接。建立了焊接過程信息采集系統(tǒng),可進行焊接過程電弧形態(tài)、熔滴過渡行為、焊接電信號等信息的采集。 (2)基于正交設計方法,設計了實驗方案。根據(jù)實驗要求選取了合適的焊接試件,設置了焊接參數(shù),規(guī)劃了焊接實驗的基本步驟。 (3)根據(jù)實驗方案進行了高壓干法GMAW焊接實驗,依次設定環(huán)境壓力為01MPa、0.4MPa、0.7MPa、1.0MPa,采集焊接過程的相關信息,分析總結了壓力對焊接過程穩(wěn)定性的影響規(guī)律,如隨著環(huán)境壓力的升高,焊接過程的穩(wěn)定性逐漸下降 (4)分別調節(jié)焊接電參數(shù)、焊絲伸出長度及保護氣成分等因素進行了焊接實驗,研究了這些因素對高壓干法GMAW的影響情況,確定了最優(yōu)的焊接參數(shù),為相關工程應用提供了參考依據(jù)。 (5)通過對比直流反接和直流正接時的焊接過程穩(wěn)定性、焊縫表面成形、焊縫截面成形情況,研究了焊接極性對高壓干法GMAW的影響。 本文研究表明,對于高壓干法GMAW,隨著環(huán)境壓力的升高,焊接過程穩(wěn)定性逐步下降,飛濺現(xiàn)象嚴重；在壓力環(huán)境下,通過采用直流正接的方式能夠明顯改善飛濺現(xiàn)象。該研究為今后高壓干法GMAW焊接的進步研究及應用奠定了基礎。
[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.

【學位授予單位】：北京化工大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：P755.1

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本文編號：1405724