基于有限元分析软件的仓泵焊接研究与应用

发布时间：2018-04-22 22:39

  本文选题：有限元分析 + 仓泵　； 参考：《电子科技大学》2011年硕士论文

【摘要】：仓泵多数在高温高压下运行,是压送式气力输送粉末状物料(如水泥、矿粉、粉煤灰、粮食、化工原料)的理想设备。因此,仓泵的焊接接头必须具有较高的强度、耐磨性,足够高的冲击韧性和较高的耐热性,并且保证接头无裂纹、末熔合、夹渣等缺陷。本课题研究的仓泵是浙江菲达环保集团公司生产低压容器中的一个主要品种,是气力输送环保配套设备的关键部件,其壳体母材是15CrMoR钢。解决15CrMoR钢焊后冷裂纹问题以获得强度高、韧性与塑性好的优质仓泵焊接接头成为仓泵生产制造过程中的关键问题。 本论文通过对仓泵壳体15CrMoR钢的化学成分和性能分析、焊接裂纹敏感性计算、裂纹敏感机理分析及焊接工艺可行性分析,结合生产实际,确定了课题研究目标是以MAG气体保护焊打底、填充,埋弧焊盖面的组合焊法为重点研究内容。采用ANSYS系统对仓泵焊接温度场和焊接应力场进行动态模拟,建立了基于ANSYS软件系统温度场、应力场的有限元分析模型,针对不同时刻焊接温度场分布,焊接应力场中残余应力的变化进行了数字分析,为16mm中厚板多层多道焊选择焊接规范提供了科学依据。 在仓泵焊接应用研究中,我们采用了不同的预热温度、焊接电流、焊接速度及线能量进行施焊,对焊接接头焊缝进行X射线探伤,力学性能试验,达到JB4730-2005《承压设备无损检测》标准中的Ⅱ级要求,焊缝外观达到GB50236-98《现场设备、工业管道焊接工程施工及验收规范》标准中的Ⅰ级要求。通过对接头金相组织进行分析,焊缝组织为细小的柱状晶,而熔合区和热影响区组织均为柱状晶铁素体+粒状贝氏体+低碳马氏体组织。研究结果表明:仓泵焊接填充材料是H13CrMoA ,要求焊前预热温度为150～180℃,打底层、填充层MAG气体保护焊保护介质为20%CO2+80%Ar,电弧电压为22±1V,焊接电流为130～170A。埋弧焊进行盖面,焊接电流为480～550,电弧电压为36～38V。焊后热处理温度为250℃,保温lh,正火温度900℃,保温1h后马上随炉冷却,采用焊后热处理方式,高温回火温度为680士100℃,保温1h。得到的焊接接头抗拉强度为560Mpa,焊缝金属(20℃)冲击韧性为79J,完全可以满足仓泵设计的技术要求。 通过本次应用研究分析,焊接热输入对接头组织和性能有重大影响,通过调整热输入能有效控制接头冷却速度,从而改善热影响区的脆化和软化现象,提高接头的强度、韧性,满足了产品的设计制造要求。 本文仓泵焊接的应用研究已用于产品焊接生产,焊接质量达到了相应国家标准规定要求。
[Abstract]:Most of the storage pumps operate at high temperature and high pressure. They are ideal equipment for pneumatic conveying of powder materials (such as cement, mineral powder, fly ash, grain and chemical raw materials). Therefore, the welded joints of bin pump must have high strength, wear resistance, high impact toughness and high heat resistance, and ensure that the joints are free of cracks, end fusion, slag inclusion and other defects. The storage pump studied in this paper is one of the main varieties of low pressure vessels produced by Zhejiang Fida Environmental Protection Group Co., Ltd. It is the key part of the supporting equipment for pneumatic transportation and environmental protection. Its shell base material is 15CrMoR steel. To solve the problem of cold crack after welding of 15CrMoR steel to obtain high strength, good toughness and good ductility, the welding joint of high quality warehouse pump becomes the key problem in the production and manufacture of warehouse pump. In this paper, the chemical composition and properties of 15CrMoR steel, the calculation of welding crack sensitivity, the mechanism of crack sensitivity and the feasibility of welding process are analyzed. The research object is focused on MAG gas shielded welding, filling and combined welding of submerged arc welding cover. The welding temperature field and welding stress field of warehouse pump are simulated dynamically by ANSYS system, and the finite element analysis model of temperature field and stress field based on ANSYS software system is established, aiming at the distribution of welding temperature field at different time. The variation of residual stress in welding stress field is analyzed numerically, which provides a scientific basis for the selection of welding specification for multi-layer and multi-pass welding of 16mm plate. In the research on the application of bin pump welding, we used different preheating temperature, welding current, welding speed and line energy to weld the welded joint. The welding seam was tested by X ray and mechanical properties. It can meet the requirements of Class 鈪，

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