文档介绍：焊透率焊接工艺分析
摘要
焊透率过低造成的直接影响就是未焊透缺陷,未焊透对焊接结构来说最直接的危害是减少承载截面,降低焊接接头的机械性能。同时,未焊透引起的应力集中远比强度降低的危害性还要承受交变载冲击载荷、应力腐蚀或低温下工作的结构,常常由此导致脆性断裂。未焊透缺陷是在役压力管道缺陷中存在的主要缺陷,研究其与焊接工艺之间的关系不仅具有重要的理论意义更具有重要的工程应用价值。
研究采用的实验材料为工业上应用比较广泛的Q235钢板材料。对Q235钢板的焊透程度进行了理论的分析后,采用不同的焊接工艺利用手工电弧焊对Q235钢板进行不开坡口留2毫米间隙的焊接实验,并利用金相实验和显微硬度实验对Q235钢板的焊透程度进行评定,利用评定结果分析焊接工艺对焊透率的影响。
焊缝的焊透率的高低直接影响焊缝的质量,例如焊透率达到80%且有熔深的桥壳,其疲劳寿命可以提高20%以上,并提高桥壳的屈服极限。如果能够研究出采用哪种焊接工艺对提高焊缝的焊透程度有有利影响,就可以减少成本而更好地提高焊接的性能。
手工电弧焊是现代工厂里应用最普遍的一种焊接方法,采用不同的焊丝和不同的焊接电流,进行一系列的焊接试验。据此,总结了不同的焊接工艺对焊透率的影响。
按JB4708—1992的要求对焊接工艺进行评定。按焊缝基本标准的对钢板的对接接头进行检测,检测表明焊缝质量接近Ⅱ级,焊缝基本无裂纹、未融合等缺陷。金相实验和显微硬度实验表明,不同的焊接工艺对焊透率的影响是不同的。
对大量实验数据进行整理,编制出了“不同的焊接工艺对钢板焊透程度的影响”,作为二氧化碳气体保护选定工艺路线的依据。
关键词:Q235钢板;焊接;焊透率;焊接工艺;未焊透

ration rate welding process analysis
Abstract
Low ration rate of the immediate impact is lack of ration defects, plete ration of the welded structure is the most direct bearing section is to reduce harm, reduce the mechanical properties of welded joints. Meanwhile, the lack of ration caused by the stress concentration lower than the strength of the dangers but also to withstand impact loads of alternating load, stress corrosion, or low temperatures, the structure of the work, which often lead to brittle fracture. plete ration defects are defects in the service Pressure the main defect of the welding process and the relationship between not only has important theoretical meaning is more important application value.
The experimental material used widely in industry for Q235 steel material in Study. Q235 steel plate ration of the extent of the theoretical analysis, using different use of manual arc welding steel plates on the Q235 does not stay open 2 mm gap groove welding experiments and experiments using metallographic and microhardness experiments Q235 steel assess the extent of ration, the use of evaluation results of butt welding process through rate.
Weld ration rate directly affects the quality of welds, for example, ration rate of 80% and a ratio