板翅式铝合金油冷器焊接工艺研究
发布时间：2018-11-27 09:54
【摘要】：机油冷却器(简称油冷器)主要功能是用于发动机润滑油的冷却,是汽车发动机冷却系统的重要零配件。如今,车用油冷器多采用多层密集排列的锯齿型错列翅片全铝油冷器,此类型的油冷器体积小,重量轻,冷却效率高,但油冷器整体结构复杂,同时又对油冷器的密封性和耐腐蚀等性能又有着非常苛刻的要求,为实现该类型油冷器翅片同芯板、芯板同前后密封板之间精密和高质量的连接,最终实现油冷器同冷却系统精密与可靠的连接,其连接方法已经成为备受关注的研究课题。本文以CA型板翅式铝合金油冷器为研究对象,首先,制定了油冷器顶板结构的电阻点焊工艺和芯体的Nocolok炉中钎焊工艺。其次,焊后分别对点焊焊接接头进行了宏观形貌、显微组织、显微硬度、拉伸性能和撕裂分析等实验分析,研究了不同工艺参数对点焊焊接接头各性能的影响规律。同时,研究了钎焊工艺参数对油冷器钎焊接头显微组织的影响,并对油冷器进行了综合性能检测,为该类型的板翅式铝合金油冷器的焊接提供了关于焊接工艺的理论基础。实验研究表明:1)点焊焊接接头由熔核、塑性环和母材三部分组成,熔核属于典型的“柱状晶+等轴晶”组织。随着电流和焊接周波的增大,焊核中心等轴晶组织逐渐粗化,柱状晶组织数量随着焊接电流的增大而减少,随着电极压力的增大而增多。2)焊接电流、焊接周波和电极压力对点焊接头的显微硬度和拉伸载荷的影响规律均有所不同,柱状晶区的显微硬度大于焊核中心,显微硬度最小值出现在热影响区。3)当焊接电流、周波和电极气压分别为22 kA、8 cyc和0.20 MPa,且预压时间和维持时间分别为25 cyc和15 cyc时,点焊焊接接头性能达到最佳值,其平均显微硬度为40.64 Hv,拉剪力为2.103 kN。4)钎缝区的组织是典型的α(Al)固溶体和Al+Si共晶相组织。钎焊工艺的最优工艺参数是:六个分区温度依次为600℃-605℃-610℃-615℃-620℃-615℃,钎焊区网带速度为320 mm/min。对油冷器进行综合性能检测试验,检测发现产品合格率高,满足生产和使用要求,表明该最优工艺参数可用于指导实际焊接生产。
[Abstract]:The main function of the oil cooler is to cool the engine lubricating oil, which is an important part of the automobile engine cooling system. Nowadays, automotive oil coolers are mostly made of multi-layer, dense arrangement of jagged staggered fin all aluminum oil coolers. This type of oil cooler is small in volume, light in weight and high in cooling efficiency, but the overall structure of the oil cooler is complex. At the same time, the sealing performance and corrosion resistance of the oil cooler are very demanding. In order to realize the precise and high quality connection between the fin of the oil cooler and the core plate, the core plate and the front and rear sealing plates, Finally, the precise and reliable connection between oil cooler and cooling system is realized. In this paper, the CA type plate-fin aluminum alloy oil cooler is taken as the research object. Firstly, the resistance spot welding process of the oil cooler roof structure and the brazing process of the core body in the Nocolok furnace are established. Secondly, the macroscopic morphology, microstructure, microhardness, tensile properties and tear analysis of spot welded joints were analyzed respectively after welding, and the effects of different process parameters on the properties of spot welded joints were studied. At the same time, the effect of brazing process parameters on the microstructure of the brazed joint of the oil cooler is studied, and the comprehensive properties of the oil cooler are tested, which provides a theoretical basis for the welding of this type of plate-fin aluminum alloy oil cooler. The experimental results show that: 1) the spot welding joint consists of three parts: nugget, plastic ring and base metal. The nugget belongs to the typical "columnar equiaxed crystal" structure. With the increase of current and Zhou Bo, the equiaxed structure of the center of the nugget gradually coarsened, the number of columnar structure decreased with the increase of welding current, and increased with the increase of electrode pressure. 2) Welding current. The effect of welding Zhou Bo and electrode pressure on the microhardness and tensile load of spot welding joint is different. The microhardness of columnar crystal zone is larger than that of the core of the welding, and the minimum value of microhardness appears in the heat affected zone. 3) when welding current, When Zhou Bo and electrode pressure were 22 kA,8 cyc and 0.20 MPa, preloading time and maintaining time were 25 cyc and 15 cyc, respectively, the properties of spot welding joint reached the optimum value, and the average microhardness was 40.64 Hv,. The microstructure of brazing seam region with tensile shear force of 2.103 kN.4 is typical of 伪 (Al) solid solution and Al Si eutectic phase. The optimum parameters of brazing process are as follows: the six zone temperatures are 600 鈩，
本文编号：2360299
[Abstract]:The main function of the oil cooler is to cool the engine lubricating oil, which is an important part of the automobile engine cooling system. Nowadays, automotive oil coolers are mostly made of multi-layer, dense arrangement of jagged staggered fin all aluminum oil coolers. This type of oil cooler is small in volume, light in weight and high in cooling efficiency, but the overall structure of the oil cooler is complex. At the same time, the sealing performance and corrosion resistance of the oil cooler are very demanding. In order to realize the precise and high quality connection between the fin of the oil cooler and the core plate, the core plate and the front and rear sealing plates, Finally, the precise and reliable connection between oil cooler and cooling system is realized. In this paper, the CA type plate-fin aluminum alloy oil cooler is taken as the research object. Firstly, the resistance spot welding process of the oil cooler roof structure and the brazing process of the core body in the Nocolok furnace are established. Secondly, the macroscopic morphology, microstructure, microhardness, tensile properties and tear analysis of spot welded joints were analyzed respectively after welding, and the effects of different process parameters on the properties of spot welded joints were studied. At the same time, the effect of brazing process parameters on the microstructure of the brazed joint of the oil cooler is studied, and the comprehensive properties of the oil cooler are tested, which provides a theoretical basis for the welding of this type of plate-fin aluminum alloy oil cooler. The experimental results show that: 1) the spot welding joint consists of three parts: nugget, plastic ring and base metal. The nugget belongs to the typical "columnar equiaxed crystal" structure. With the increase of current and Zhou Bo, the equiaxed structure of the center of the nugget gradually coarsened, the number of columnar structure decreased with the increase of welding current, and increased with the increase of electrode pressure. 2) Welding current. The effect of welding Zhou Bo and electrode pressure on the microhardness and tensile load of spot welding joint is different. The microhardness of columnar crystal zone is larger than that of the core of the welding, and the minimum value of microhardness appears in the heat affected zone. 3) when welding current, When Zhou Bo and electrode pressure were 22 kA,8 cyc and 0.20 MPa, preloading time and maintaining time were 25 cyc and 15 cyc, respectively, the properties of spot welding joint reached the optimum value, and the average microhardness was 40.64 Hv,. The microstructure of brazing seam region with tensile shear force of 2.103 kN.4 is typical of 伪 (Al) solid solution and Al Si eutectic phase. The optimum parameters of brazing process are as follows: the six zone temperatures are 600 鈩，
本文编号：2360299
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