大型齿轮座下箱体焊接工艺

Research on Welding Technology of Lower Box of Large Gear Seat

国内某产品使用的大型齿轮座下箱体胚料,广泛采用铸造成型工艺生产,由于结构原因,其铸造工艺复杂、缺陷多、产品率低、生产成本较高。结构“铸改焊”后,工艺相对简单、焊接质量易于保证、产品合格率及材料利用率高,可大幅降低制造成本,因此焊接齿轮下箱体应用前景广泛。但大型齿轮下箱体焊接中,因材料板厚大,焊缝密集,焊接应力大,极易产生裂纹,同时焊接变形大,焊后加工尺寸难以保证。本文针对某大型齿轮座下箱体的焊接,在结构工艺分析的基础上,制定了合理的焊接工艺并得以实施。结果表明:采用CO;气体保护焊与富氩气体保护焊相结合的焊接方法,选择正确的放量尺寸、焊接顺序、焊接参数、坡口形式和相应的焊前、焊中及焊后热处理等工艺,完全能够满足结构的设计要求。

The casting molding process is widely used in the production of large gear seat in the domestic product, because of the case-structural reasons, the problem of the process is complicated, the casting defect is large, the product quality rate is low and the production cost is higher. After the construction of "casting change to welding", the technology is relatively simple, the welding quality is easy to guarantee, the highly product qualification rate and highly efficiency of the material can greatly reduce the manufacturing cost, so the application prospect of the welding in the case gear is broad. However, it is difficult to ensure the processing size of welding, because the material plate is thick and large, the weld is dense, the welding stress is large, it is easy to produce the crack, and the welding deformation is large, and the processing size is difficult to guarantee.This paper mainly studies the welding process of the lower box of large gear seat. On the basis of process analysis,a reasonable welding process is developed and implemented. The results show that the welding method combined with CO_(2)shielded welding and argon shielded welding can fully meet the design requirements of the structure by choosing the right welding size, welding sequence, welding parameters, groove form and corresponding welding processes such as prewelding, in-welding and post-welding heat treatment.