共查询到17条相似文献,搜索用时 62 毫秒
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多层多道焊时,后层焊道的热量会对前层焊道起到热处理的作用,使前层焊道的热影响区组织尤其是过热区组织发生转变,进而改变接头的力学性能.文中采用数值模拟技术,从温度场与组织转变对应关系的角度分析特定焊接工艺下的单丝、双丝窄间隙埋弧焊坡口侧壁过热粗晶区的组织演化过程.模拟结果表明,针对两种焊接形式,焊道厚度为4 mm时,单丝焊原过热区约有50%最终经历正火作用,双丝焊约有55%~60%.针对双丝焊前后焊丝的不同作用,改变焊接工艺,适当降低前丝焊接电流,可以获得更小的坡口侧壁过热粗晶区,并且后层焊道对前层焊道的热处理效果更好. 相似文献
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焊接曲轴是近代曲轴制造工艺中一个重要成就.采用窄间隙埋弧焊方法焊接曲轴,不仅保证了焊缝的强度和刚度,而且节省了材料、降低了焊接应力、减少了焊接缺陷. 相似文献
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双丝窄间隙埋弧焊微机控制系统的研究 总被引:1,自引:0,他引:1
本文采用MCS—51单片机,利用双CPU分时主—从机技术,解决了双丝窄间隙埋弧焊系统多复杂信息量的处理要求所带来的技术难题,实施了该系统的微机控制,所研制的微机控制系统由EPROM、RAW、I/O、CTC、A/D等专用芯片,LED显示,键盘矩阵,打印机,光电隔离等电路组成,系统可实现:焊接过程状态及焊接规范参数的预置并可以修改,在焊接过程中,对焊接规范参数进行实时检测,反馈控制并动态显示,定时自动打印焊按规范本好,以便存档记录,为厚壁压力容器的焊接质量检测提供了可靠的依据。该系统还可以实现环缝焊接时焊接线速度的控制。系统I/O口全部采用光电隔离,整机抗干扰能力强,功能齐全,结构合理,运行可靠。 相似文献
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采用HSS-2500型双丝窄间隙埋弧焊设备,进行了焊接工艺试验,先后做了板焊和锻焊结构的试板与试环的焊接工艺评定。通过对试验结果的分析,确定了工艺参数,并成功地将该工艺应用到高压加热器产品的焊接中。 相似文献
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1 液压机缸体制造概况缸体是液压机的重要载荷部件 ,其形状见缸体示意图 1a。工作压力为 2 5MPa ,材料为 35 #锻钢 ,经粗加工后的缸体毛坯参数见表 1。表 1 粗加工后缸体毛坯参数直 径d/mm长 度L/mm壁 厚δ/mm质 量/t46 0~ 2 0 0 0 80 0~ 3 0 0 0 5 0~ 30 0 0 .5~ 2 0图 1 液压机缸体示意图粗加工前的缸体毛坯以往大都采用实芯锻造、机加工挖空的习惯方式 ,因此锻造毛坯不仅浪费钢材 ,而且加工周期长 ,费用大。随着焊接新技术的不断推广应用 ,一改整体结构为分体结构 ,由筒 -底焊接而成(图 1b、c) ,率先采用较手… 相似文献
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直径4000mmPKM加压气化炉的压力传动箱、灰锁、材质为15Mo3低合金耐热钢,使用哈尔滨焊接研究所研制的双丝窄间隙埋弧焊设备,采用焊丝9MnMo4.5+SJ101焊剂,焊接了窄间隙焊缝。结果表明,接头质量和力学性能均能满足标准和图纸的技术要求。 相似文献
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针对旋转电弧窄间隙MAG焊焊缝成形研究需要,采用Ansys软件对旋转电弧窄间隙MAG焊接温度场进行数值模拟,研究焊缝成形的影响因素.考虑旋转电弧窄间隙MAG焊特点,实现热源模型旋转加载和旋转电弧窄间隙焊接三维温度场数值计算,模拟温度场结果与试验焊缝形貌吻合良好.为进一步提高计算效率,根据热源等效和旋转电弧热源分布特点,提出了一种类似马鞍形圆环的等效热源,侧壁熔深模拟结果与实际较符合,且计算效率大为提高.研究结果为进一步的熔深控制和焊接变形研究奠定基础. 相似文献
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窄间隙MAG焊(NG-MAG)过程中电弧摆动和分时熔合技术是保证侧壁熔合良好的关键. 通过对摆动电弧移动过程中速度大小和方向不断变化规律的分析,在经典双椭球热源模型的基础上采用坐标变换法建立了NG-MAG立焊摆动电弧动态热源模型. 温度场模拟结果表明,NG-MAG立焊热循环曲线呈"多峰"现象,焊缝表面成形似"积木"而截面成形似"哑铃",与试验结果基本吻合. 分析认为"多峰"现象主要由电弧热源逐次逼近而后远离所致,而"积木"和"哑铃"的成形特点与移动过程中电弧速度(热输入)的周期变化及焊接熔池的动态变化高度相关,上述热特点对后续进行NG-MAG立焊组织演化研究提供技术支持. 相似文献
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In this paper, the droplet transfer in oscillating arc narrow gap gas metal arc ( GMA ) welding was studied. According to the experimental results, the oscillating arc has effect on the droplet transfer mode. The droplet transfer frequency in narrow gap groove is higher than that in bead-on-plate welding. Because of the change of arc location in narrow gap groove, the droplet transfer in oscillating arc narrow gap changes regularly. The droplet transfer frequency near groove sidewall is higher than that at the middle of narrow gap groove. 相似文献
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针对大厚板,常用的焊接方法需要开大角度坡口,焊接时采用多层多道焊,焊件往往内部应力较大,变形严重。而窄间隙焊接采用窄而深的坡口,在厚板焊接中具有效率高等优势。针对当前常用的厚板窄间隙焊接技术,本文中主要总结了国内近几年在激光窄间隙焊接,电弧窄间隙焊接和超窄间隙焊接三个方面的研究进展。 相似文献
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Nobuhisa Ochi Shigetaka Okano Masahito Mochizuki Junji Shimamura Nobuyuki Ishikawa 《Welding International》2013,27(3):174-183
In recent years, in order to reduce the costs of transportation and construction of pipelines, which are often constructed using multiple-electrode submerged arc welding (SAW), higher joint performance is required. Therefore, there has arisen the need to understand theoretically and control appropriately metallurgical and mechanical characteristics in heat-affected zone (HAZ), which has a significant influence on the strength and toughness of welded joints. Commonly, metallurgical phenomena in HAZ are evaluated based on the highest temperature and the cooling rate. Therefore, in order to control metallurgical and mechanical characteristics in HAZ by means of the welding conditions, evaluating the temperature distribution and the temperature history near the melted zone is essential. However, a detailed investigation of the temperature distribution for multiple-electrode SAW has not yet been carried out enough. In this study, in order to investigate the temperature distribution and histories during multiple-electrode SAW, the experimental results are compared with the theoretical results. In the theoretical analysis, the temperature rise equation in multiple heat sources welding is developed using the method of summation. Furthermore, on temperature distribution during welding, the effects of multiple heat sources, such as the number of heat sources and the distance between each electrodes, are considered quantitatively through the thermal conduction theoretical analysis. As the result, the distance between lead heat source and final heat source primally influences the area with the difference between a single heat source welding and multiple heat sources welding. Based on the results, it is expected to control temperature distribution near melted zone by more appropriate heat input characteristics, which is depended on heat source arrangement. 相似文献