铁铬基钎料真空钎焊钢质油冷器试验研究
发布时间：2018-08-07 13:50
【摘要】：本文针对铁铬基钎料在钢质油冷器钎焊中的应用开展了试验研究。通过对多种不同型号和结构的产品的试制,发现产品中存在虚焊、接头强度低、安装板钎缝经压平后开裂和母材过多溶解等问题。为研究虚焊产生的原因,对铁铬基钎料和纯铜钎料的润湿和填缝性能进行对比实验。结果表明,铁铬基钎料填缝性能与纯铜钎料相当,但润湿性不如后者。此外,由于翅片尺寸精度不高,膏状钎料涂覆过程中出现不均匀等缺陷,可能是虚焊产生的原因。分别采用T形试样和楔形试样研究了钎角和钎缝平行段的溶解情况。随着钎料用量和钎焊温度的提高,钎角溶解面积和溶解深度均增加。随着间隙的增大,平行段溶解深度增大。溶解过程可能与钎料中的P向晶界扩散造成晶界优先溶解有关。根据上述实验,研究了14.4型油冷器中每个凸台适宜的焊膏用量。对比研究了铁铬基钎料和纯铜钎料不同间隙下钎焊304-304和304-Q235接头的微观组织和剪切强度。0-0.02mm间隙下,钎缝中只含有少量不连续磷化物。随着间隙增大,钎缝中心逐渐形成连续的共晶区,并且比例逐渐增大,接头强度先下降后稳定,断裂形式由韧性逐步变为脆性。升高温度可以减少钎缝中的磷化物含量,但只在小间隙下才能提高接头强度。通过重新设计芯片,使凸台分布更密集,改善了翅片与芯片间加压的均匀性,减小了装配间隙,虽然仍有少量虚焊,但接头强度提高,使产品达到所有可靠性试验标准。通过改进钎料预置方式和焊模平面度,提高了产品强度和稳定性。安装板和隔圈使用纯铜钎料,通道内使用铁铬基钎料,可以一次完成钎焊,并解决安装板钎缝压平后开裂问题。对铁铬基钎料钎焊的钢质油冷器进行性能试验和热油腐蚀试验,产品满足规定的换热性能要求和低铜要求。目前已将铁铬基钎料成功应用于14.4型油冷器中,实现了小批量生产。
[Abstract]:In this paper, the application of Fe-Cr based solder in steel oil cooler brazing has been studied. Through the trial production of many kinds of products of different types and structures, it is found that there are some problems in the products, such as virtual welding, low joint strength, cracking of the brazing joint of the mounting plate after pressing and excessive dissolution of the base metal. In order to study the causes of virtual welding, the wetting and filling properties of Fe-Cr based solder and pure copper solder were compared. The results show that the filler joint properties of Fe-Cr based solder are similar to those of pure copper solder, but wettability is not as good as that of pure copper filler metal. In addition, due to the inaccuracy of fin size and the inhomogeneity of paste solder coating process, it may be the reason of virtual welding. The dissolution of the brazing angle and the parallel section of the brazing seam were studied by using T-shaped specimen and wedge-shaped specimen respectively. With the increase of filler metal content and brazing temperature, the dissolved area and depth of soldering angle increase. With the increase of the gap, the dissolution depth of the parallel segment increases. The dissolution process may be related to the preferential dissolution of the grain boundary due to the diffusion of P to the grain boundary in the solder. According to the above experiments, the suitable amount of solder paste for each platform of 14.4 oil cooler was studied. The microstructure and shear strength of 304-304 and 304-Q235 joints brazed with iron-chromium based solder and pure copper solder with different gaps were studied. Only a small amount of discontinuous phosphates were found in the brazing joints. With the increase of the gap, a continuous eutectic zone is formed in the center of the brazing seam, and the ratio increases gradually. The strength of the joint decreases first and then stabilizes, and the fracture form changes from toughness to brittleness. The content of phosphates in brazing seam can be reduced by increasing temperature, but the strength of joint can be improved only in small gap. By redesigning the chip, the distribution of the punch is denser, the uniformity of pressure between the fin and the chip is improved, and the assembly gap is reduced. Although there is still a small amount of virtual welding, the strength of the joint is increased, which makes the product meet all the reliability test standards. The strength and stability of the product were improved by improving the preposition of solder and the flatness of the welding die. Using pure copper solder for mounting plate and ring, and iron and chromium base solder for channel, the brazing can be completed at one time, and the crack problem can be solved after the brazing joint of the mounting plate is flattened. The performance test and hot oil corrosion test of the steel oil cooler brazed with iron-chromium solder are carried out. The products meet the requirements of heat transfer performance and low copper. At present, Fe-Cr-based solder has been successfully applied in 14.4 oil cooler, and small batch production has been realized.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG454
本文编号：2170220
[Abstract]:In this paper, the application of Fe-Cr based solder in steel oil cooler brazing has been studied. Through the trial production of many kinds of products of different types and structures, it is found that there are some problems in the products, such as virtual welding, low joint strength, cracking of the brazing joint of the mounting plate after pressing and excessive dissolution of the base metal. In order to study the causes of virtual welding, the wetting and filling properties of Fe-Cr based solder and pure copper solder were compared. The results show that the filler joint properties of Fe-Cr based solder are similar to those of pure copper solder, but wettability is not as good as that of pure copper filler metal. In addition, due to the inaccuracy of fin size and the inhomogeneity of paste solder coating process, it may be the reason of virtual welding. The dissolution of the brazing angle and the parallel section of the brazing seam were studied by using T-shaped specimen and wedge-shaped specimen respectively. With the increase of filler metal content and brazing temperature, the dissolved area and depth of soldering angle increase. With the increase of the gap, the dissolution depth of the parallel segment increases. The dissolution process may be related to the preferential dissolution of the grain boundary due to the diffusion of P to the grain boundary in the solder. According to the above experiments, the suitable amount of solder paste for each platform of 14.4 oil cooler was studied. The microstructure and shear strength of 304-304 and 304-Q235 joints brazed with iron-chromium based solder and pure copper solder with different gaps were studied. Only a small amount of discontinuous phosphates were found in the brazing joints. With the increase of the gap, a continuous eutectic zone is formed in the center of the brazing seam, and the ratio increases gradually. The strength of the joint decreases first and then stabilizes, and the fracture form changes from toughness to brittleness. The content of phosphates in brazing seam can be reduced by increasing temperature, but the strength of joint can be improved only in small gap. By redesigning the chip, the distribution of the punch is denser, the uniformity of pressure between the fin and the chip is improved, and the assembly gap is reduced. Although there is still a small amount of virtual welding, the strength of the joint is increased, which makes the product meet all the reliability test standards. The strength and stability of the product were improved by improving the preposition of solder and the flatness of the welding die. Using pure copper solder for mounting plate and ring, and iron and chromium base solder for channel, the brazing can be completed at one time, and the crack problem can be solved after the brazing joint of the mounting plate is flattened. The performance test and hot oil corrosion test of the steel oil cooler brazed with iron-chromium solder are carried out. The products meet the requirements of heat transfer performance and low copper. At present, Fe-Cr-based solder has been successfully applied in 14.4 oil cooler, and small batch production has been realized.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG454
【参考文献】
相关期刊论文 前2条
1 陈建民,朱长福;真空钎焊不锈钢接头的钎缝组织和相组成特征[J];石油大学学报(自然科学版);1999年02期
2 孙磊;秦优琼;;元素Cu对BNi-7钎料组织和润湿性能的影响[J];上海工程技术大学学报;2014年04期
，本文编号：2170220
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