热交换器管板焊接工艺设计与质量控制（本科毕业论文设计）.doc

摘    要
　　　
　　　气氨加热器多数工作在高温、高压和腐蚀介质的环境中，管板接头往往是最薄弱、最易破坏的部位，因此对焊接质量的要求很高。本论文为寻求最佳的焊接工艺，从各个方面进行了探讨、分析、研究，最后制定出了一条合理的焊接工艺路线和质量控制方法，从而能够获得强度高、塑性和韧性好的优质焊接接头，最终获得优质合格的产品。
　　　通过分析热交换器管板结构和母材（0Cr18Ni9）的焊接性，弄清楚焊接时可能出现的缺陷和应采取的防止措施，并选取了手工TIG焊。通过对TIG焊工艺的分析，选出了合适的工艺参数和焊接设备，制定出了符合产品设计要求的优良的焊接工艺。最后分别从焊前、焊中和焊后三个方面形成了一个质量控制和检验的完整体系，确保了管板焊接接头质量满足设计和相关技术条件要求。
　　　本文对母材0Cr18Ni9奥氏体不锈钢的焊接性分析和制定出的焊接工艺以及提出的质量控制体系具有一定的理论研究价值和较高的实际工程应用价值。
　　　
　　　
关键词：管板，手工TIG，焊接工艺，质量控制

ABSTRACT

　　　Most of the ammonia gas heaters work in the environment of high temperature, high pressure and corrosive media, and the weakest and most vulnerable to damage sites are often the pipe-board joints. Therefore, the welding quality must be very good. To find the best welding technology, by studying, discussing and researching many aspects, finally this paper draws up a reasonable route for welding technology and a method to control the quality, so as to acquire the superior welded joints with high strength, good plasticity and excellent tenacity, aiming to make high-quality products.
　　　By analyzing the pipe-board structure of the heat exchanger and the weld-ability of the base material (0Cr18Ni9), this paper finds out the possible defects and preventive measures, and selects Manual-TIG welding. By analyzing the TIG welding technology, the appropriate technology parameters and welding equipment are selected, and a good welding technology in accordance with the requirements of design of product is drawn up. Finally this paper constitutes a system of quality controlling and testing from before the welding operation, welding operation and after the welding operation, to ensure that the quality of the welding joint of pipe-board can meet the requirements of design and related technology conditions.
　　　In this paper, the weld-ability analysis of the base material (0Cr18Ni9) which is austenitic stainless steel and the welding technology drawn up and the system of quality controlling and testing are embodied with a certain theoretical value and practical value.
　　　
　　　
Key words：pipe-board,  Manual-TIG,  welding technology,  quality controlling
   

目   录

中文摘要 Ⅰ
ABSTRACT Ⅱ
1绪论 1
  1.1 国内外研究现状 1
  1.2 本次设计的构思和预期结果 2
2管板结构分析 3
  2.1 热交换器整体结构分析 3
　2.2 热交换器管板-管子结构分析 3
3母材（0Cr18Ni9）的焊接性分析 5
  3.1 0Cr18Ni9奥氏体不锈钢的化学成份及性能 5
　3.2 熔化焊常见缺陷及防止措施 6
　3.3焊接接头的耐蚀性....................................................................................7
    3.3.1 晶间腐蚀 7
　　3.3.2 应力腐蚀开裂...................................................................................9
　3.4焊接接头的热裂纹....................................................................................9
　3.5焊接接头的“等强性” 10
4 热交换器管板焊接工艺分析...............................................................11
　4.1 焊接方法的选用.....................................................................................11
　　4.1.1 0Cr18Ni9奥氏体不锈钢焊接时的工艺特点.............................................11
　　4.1.2 管板焊接接头结构的焊接工艺分析.......................................................11
　　4.1.3 确定焊接方法..................................................................................11
　4.2 焊接规范参数对接头性能的影响................................................................14
　　4.2.1 焊缝形状尺寸对焊缝质量的影响..........................................................15
　　4.2.2 焊接规范参数对焊缝成形的影响..........................................................15
　　4.2.3 确定焊接电流..................................................................................17
　　4.2.4 初步确定电弧电压............................................................................17
　4.3 焊接材料的选用.....................................................................................17
　　4.3.1 钨极的选用.....................................................................................18
　　4.3.2 氩气..............................................................................................19
　　4.3.3 焊丝..............................................................................................19
4.4焊接设备的分析与选配................................................................................19
　　4.4.1 焊接电源分析..................................................................................20
　　4.4.2 控制装置........................................................................................22
　　4.4.3 焊枪..............................................................................................22
　　4.4.4 小结..............................................................................................23
5 热交换器管板焊接工艺设计...............................................................25
6 焊接接头质量控制及检验...................................................................27
　6.1 焊前质量控制........................................................................................27
　6.2 焊接过程中质量控制...............................................................................28
　6.3 焊后质量检验........................................................................................29
7 结论 32
参考文献 33
致谢 34