共查询到18条相似文献,搜索用时 140 毫秒
1.
为了提高镀锌钢板点焊电极寿命,作者提出了镀锌钢板点焊电极的深冷处理方法。采用不同深冷处理工艺参数处理了点焊镀锌钢板的Cr—Zr—Cu合金电极,用这些电极进行了镀锌钢板点焊电极寿命试验并与未深冷处理的电极寿命进行了比较。用扫描电子显微镜对深冷处理电极进行了背散射及面扫描分析,用X射线衍射法观测了深冷处理前后的电极晶粒度,测试了电极在深冷处理前后的电阻率。通过对深冷电极微观结构的观测及电极性能的测试,探讨了深冷处理提高镀锌钢板点焊电极寿命的机理。研究结果表明,深冷处理提高了镀锌钢板点焊电极基体的致密性,改变了合金元素的分布,细化了电极材料的晶粒,提高了镀锌钢板点焊电极的导电、导热能力及电极抗压渍变形的能力,从而提高了镀锌钢板点焊电极的寿命。 相似文献
2.
3.
试验研究了超高强度硼钢板/镀锌双相钢板的电阻点焊接头质量缺陷及其产生原因,通过正交试验设计,重点讨论了焊接电流、通电时间和电极压力对点焊接头强度的影响.结果表明:超高强度硼钢板/镀锌双相钢点焊中超高强度钢板侧更易出现飞溅和烧穿问题,通电时间和焊接电流强度时点焊接头拉剪强度影响显著,这类钢板组合的焊接应优先采用大电流、短... 相似文献
4.
5.
6.
镀锌钢板电阻点焊时由于锌层的影响电极损耗非常严重。以厚0.8mm家电用热镀纯锌钢板DX51D+Z为研究对象,探究在正交试验优化焊接参数后,热镀锌钢连续点焊时焊接接头质量变化的规律和电极损耗的特点。结果表明,当采用I=11 kA、P=2 500 N、T=13 cyc的点焊工艺参数组合可获得力学性能最佳的点焊接头;连续点焊试验初期(150点前)焊点力学强度稳定且焊点成形较好,焊接后期(150~300点)接头力学强度波动大,焊接状况不稳定;电极损耗至失效是接头质量急剧下降的主要原因,电极失效形式为头部塑性变形、端面坑蚀和Cu-Zn合金化,在本试验条件下,Cr-Zr-Cu电极焊至150点后显现不稳定现象,电极寿命约280点;失效电极端面的Cu-Zn合金层约65μm。 相似文献
7.
8.
介绍了汽车生产上的镀锌钢板电阻点焊新工艺,分析了点焊工艺参数对接头拉剪强度及表面质量的影响,并推荐了一般接头点焊的工艺规范参数的参考值。 相似文献
9.
通过正交试验法研究了焊接电流、焊接时间和电极压力对热浸镀锌低碳钢板点焊接头抗剪切力的影响规律,并分析最佳焊接工艺参数下点焊接头的微观组织、硬度分布和抗剪切力.结果表明,焊接电流对点焊接头抗剪切力影响最大,最佳焊接工艺参数为:焊接电流13 kA、焊接时间80 ms、电极压力4 kN,在该参数下点焊接头抗剪切力为8.637... 相似文献
10.
为研究深冷处理对铝合金点焊电极烧损的影响,采用深冷处理和未深冷处理两种铝合金点焊电极进行了点焊工艺试验,观测了两种电极端面宏观形貌和焊点表面宏观形貌。测试了达到未深冷处理电极寿命焊点数时两种电极端面的显微硬度。采用X射线衍射方法对达到未深冷处理电极寿命焊点数时的两种电极端面进行了分析。研究结果表明:在点焊工艺试验过程中,在一定的焊点数条件下,深冷处理电极端面和所焊焊点表面比较光亮、圆整;电极端面的显微硬度较低,并且分布均匀;电极端面未发现烧损后的产物,深冷处理使电极烧损程度显著降低。 相似文献
11.
目的了解TiB_2-ZrB_2/Ni涂层电极点焊镀锌钢板时的失效机理。方法通过扫描电镜(SEM)、X射线衍射仪(XRD)、显微硬度测试等表征方法,研究TiB_2-ZrB_2/Ni涂层点焊电极点焊镀锌钢板时表面结构、物相及性能的变化。结果 TiB_2-ZrB_2/Ni涂层电极对提高点焊电极寿命有很大帮助,点焊电极寿命可提高5倍左右。涂层使点焊电极表面的硬度得以明显提高,减缓了点焊电极端部塑性变形的进程。ZrB_2-TiB_2/Ni涂层在一定程度上减缓了钢板镀层与点焊电极产生合金化反应的进程。结论 ZrB_2-TiB_2/Ni涂层电极由于具有一定的塑性,点焊过程中涂层不会出现完全脱落现象。涂层作用一直持续至电极失效,电极失效的形式主要表现为塑性变形。 相似文献
12.
采用冷金属过渡的方法对AZ31B变形镁合金和镀锌钢板进行搭接点焊试验,运用正交试验法优化工艺参数,同时利用光学显微镜、扫描电镜和万能拉伸试验机对焊接接头的微观组织和力学性能进行研究.结果表明,运用冷金属过渡方法能够获得成形美观和性能良好的焊接接头;工艺参数显著性顺序为镀锌钢板孔径大小、送丝速度、点焊时间;接头为典型的点熔钎焊接头,由钎焊结合区和熔焊结合区组成;接头的抗拉剪载荷可达3.12 kN,远大于相同尺寸下镁镁点焊试样的抗拉剪载荷,接头的断裂方式为剪切型断裂和撕裂型断裂. 相似文献
13.
《中国焊接》2021,(2)
The present paper investigates the welding forming, microstructure and shear tensile test of lap joints with large thickness ratio which were fabricated by laser screw welding(LSW) and resistant spot welding(RSW). The comparison was conducted on two kinds of lap joints, galvanized sheet and hot pressed steel(GS-HPS), galvanized sheet and high strength steel(GS-HS). The microstructure and fracture morphology were analyzed by optical microscope. It was demonstrated that with large thickness ratio the sound lap joint of GS-HS could be obtained by LSW regardless of the irradiation of laser beam from thick metal to sheet or otherwise, and the morphology shows it is better when the laser is irradiated on the thick metal. Nevertheless, when the laser beam was applied on thick metal of HPS, blind hole or blowhole was formed in the center of joint, which is attributed to the shrinkage during solidification of the molten pool. Small pores or dispersed porosity appeared on the faying face of the joint without predetermined gap which provides the degassing. However, the increase of predetermined gap could reduce the shear strength and nugget size. Two kinds of joints made by LSW have superior shear strength than those made by RSW when the laser were applied on galvanized sheet. 相似文献
14.
Deep cryogenic treatment technology of electrodes is put forward to improve electrode life of resistance spot welding of aluminum alloy LF2.Deep cryogenic treatment makes electrode life for spot welding aluminum alloy improve.The specific resistivity of the deep cryogenic treatment electrodes is tested and experimental results show that specific resistivity is decreased sharply.The temperature field and the influence of deep cryogenic treatment on the electrode tip temperature during spot welding aluminium alloy is studied by numerical simulation method with the software ANSYS.The axisymmetric finite element model of mechanical,thermal and electrical coupled analysis of spot welding process is developed.The numerical simulation results show that the influence of deep cryogenic treatment on electrode tip temperature is very large. 相似文献
15.
DP590GA热镀锌双相钢电阻点焊接头性能 总被引:3,自引:2,他引:1
针对热镀锌双相钢板(DP590GA)电阻点焊接头问题,研究了接头正拉和拉剪强度随焊接电流的变化规律,并与普通双相钢板(DP590)点焊接头试验结果进行了比较,同时结合两种钢板点焊熔核尺寸随焊接电流的变化以及SEM能谱分析得出的熔合区锌残留量情况,分析了影响热镀锌钢板点焊接头强度的主要原因.结果表明:当其他焊接参数一定时,DP590GA与DP590点焊接头强度和熔核尺寸随着焊接电流的变化趋势在焊接电流各个阶段有所不同,而熔核区的残留锌量随焊接电流的减小而增加,从而揭示了锌层使点焊区域接触电阻降低和焊接电流密度减小引起的熔核直径减小、熔合区残留锌量增加以及锌层更易引起点焊飞溅三个因素在不同的焊接电流范围内对点焊接头强度的影响作用. 相似文献
16.
A group of projection welding experiments and joints tension-shear tests are carried out for cold-rolled steel sheets, galvanized steel sheets (GSS) without treatment, GSS with phosphating and GSS with surface greasing, respectively. The experimental results are regressively analyzed on the computers, then the projection welded joint tension-shear strength curve and the perfect welding currents range of each material are obtained. The results show that surface treatments of galvanized steels have effects on their spot weldabilities. Among the four kinds of materials, GSS with surface greasing have the worst spot weldability, for they need higher welding current and have a narrow welding currem range. 相似文献
17.
针对汽车车身常用的镀锌钢板(GMW2和DP600)的点焊性能预测问题进行了研究,引入人工神经网络模型来描述点焊工艺参数空间同焊点接头质量空间的映射关系;在对普通网络存在的缺陷问题进行深入分析的基础上,结合大量试验综合考虑,对网络模型进行了优化改进;然后将试验得到的大量点焊工艺参数与相应点焊接头质量的试验数据提供给神经网络学习.结果表明,学习后的优化神经网络模型能够准确有效地预测焊接电流对点焊熔核直径、压痕深度以及拉剪强度的影响规律.亦即该优化神经网络模型可有效地实现对车身镀锌钢板点焊性能的预测,且预测精度和准确率较高,符合工程需要,具有一定的实用价值. 相似文献