激光焊接工艺参数对锆4合金焊缝成形的影响

本文研究了激光焊接工艺参数对Ｚｒ－４合金焊缝成形的影响。结果表明：当激光功率一定时,焊缝计算存度与宽度随着焊接速度的增加三小,当焊接速度一定时,焊缝计算厚度与宽度随关激光功率的增加而增加;同时入焦量的变化对Ｚｒ－４合金的熔透也有很大的影响。对于一定厚度的材料,在透镜焦距确定后有一个合适变量,并存在一个最佳入焦量,可得到最大的焊缝成形系数。在本试验条件下,入焦量为２．１８～２．９５ｍｍ。     

高强镀锌钢的CO2激光焊接研究

在CO2激光焊接加工中,影响高强镀锌钢板焊接质量的因素有很多,此处根据试验加工对相应因数进行了分析,并给出了一套可以有效控制焊接高强钢加工质量的工艺参数,从而确保高强镀锌钢的焊接质量。     

汽车用高强钢数控激光焊接工艺对质量的影响

采用正交优化设计试验方案,综合考虑影响高强钢数控激光焊接质量的工艺参数,通过镀锌高强钢的激光焊接试验研究,对试件焊缝的力学性能试验、焊缝金相及显微组织试验、焊接接头的SEM能谱分析和焊缝盐水腐蚀试验,表明镀锌高强钢数控激光焊接工艺可以获得较高的焊接质量。提出了可以有效控制焊接镀锌高强钢加工质量的试验参数。     

600MPa级汽车用高强钢激光焊接工艺研究

以汽车用先进高强钢DP600为研究院对象,采用SW500脉冲激光焊机对其进行焊接。探索了不同工艺下焊缝的成形质量。     

激光-电弧复合焊接高强钢的性能

为了研究焊接参数对激光-电弧复合焊接性能的影响,采用了2 k W光纤激光器和MAG(熔化极活性气体保护焊)复合焊接780 MPa高强钢板,通过高速摄像机观察了熔滴过渡形式及激光(或电弧)先导的等离子体形态,研究了激光(或电弧)先导的特性、激光与电弧间距离、离焦量、MAG电流和熔滴过渡形式对激光-电弧复合焊接性能的影响.结果表明,电弧先导的焊缝成形更好;等离子体不仅影响焊缝形状,而且影响激光-电弧间最佳距离;激光与电弧间距对熔宽的影响较小;焊接电流影响焊缝形状和熔深,随着焊接电流的增加,熔深增加,当离焦量为-2 mm时熔深最大.     

外加横向电流作用下的铝合金CO_2激光焊接研究

研究了外加横向电流对铝合金CO_2激光焊接焊缝成型的影响。实验通过布置在熔池两侧并随激光同步运动的钨电极向熔池中提供横向电流。实验结果表明,当外加横向电流以后,焊缝的深度和宽度随电流的增大而增大,但深度的增加比宽度的增加更明显;熔深和熔宽的改变只与电流的大小有密切关系,而电流方向对其影响不明显。     

采用填充焊丝激光焊接工艺的研究

分析了采用填充焊丝激光焊接的加工原理、工艺特点和技术关键。工艺研究表明，采用填充焊丝激光焊接可以大为改善焊缝的冶金性能，提高焊缝质量，降低激光焊接工艺对工件坡口加工精度的要求，并可以实现大厚度板的窄间隙激光焊接。     

Nd:YAG激光+CMT电弧复合热源平焊工艺参数对焊缝成形的影响

以304不锈钢为对象,借助焊缝成形参数来评价YAG激光+CMT电弧复合热源平焊焊缝的成形特征,研究了Nd:YAG激光+CMT复合热源平焊过程中焊接工艺参数对焊缝成形的影响.结果表明,在CMT电弧焊接中加入激光可以改善平焊焊缝成形;与其它复合热源焊接相对比激光功率对熔深影响较大,对平焊焊缝成形的影响程度与焊接电流有关;采用大的光丝间距有利于焊缝金属的铺展;离焦量对平焊焊缝的熔深影响明显,对焊缝金属铺展性的影响可以忽略不计.     

硅钢带激光焊接工艺实验研究

采用CO2激光焊接器对硅含量较高的硅钢带进行激光焊接工艺实验,研究线能量及焊接前后热处理加热功率对硅钢带焊接接头组织和硬度的影响。结果表明,一定范围内,随着线能量的增加或焊接前后热处理加热功率的提高,硅钢焊缝组织中的条状铁素体逐渐变成块状,M-A组元减少,同时,焊缝到母材的硬度梯度也逐渐降低。经多次实验,最终确定最佳焊接工艺为4 500 mm?min-1×10.8 k W×26 k W×32 k W,其焊缝满足硅钢带后续的轧制要求。     

高强铝锂合金激光焊接研究进展

铝锂合金被认为是一种很有发展前途的航空航天轻质结构材料, 而激光焊接是实现铝合金结构优质、高效连接的一种先进方法.铝锂合金比常规铝合金具有更高的氢气孔敏感性, 焊接时极易产生氢气孔;进行激光深熔焊接时, 焊接过程的不稳定也可能导致小孔型气孔产生.铝锂合金属焊接时也存在焊接热裂纹问题, 这主要与合金元素及焊接凝固过程有关.接头显微组织、焊接成形及焊接缺陷的存在均会影响接头的力学性能.介绍了铝锂合金激光焊接现状, 重点讨论了铝锂合金激光焊接过程中气孔和裂纹的产生与防止、焊接接头的显微组织和力学性能.最后, 介绍了2060-T8和2099-T83新型高强铝锂合金T型接头双光束高亮度固体激光焊接的最新进展.     

Comparative Study on Microstructures of Zincalume Steel (G550) Welded Joint Between Metal Inert Gas and Laser Beam Welding

Zincalume steel (G550) is commonly used in various construction fields because of its high corrosion resistance and good mechanical properties. In recent years, a number of steel companies have massively produced zincalume steel (G550) with large volumes of waste. For the reduction of massive industrial wastes, the zincalume steel (G550) was welded in the lap joint configuration using different welding parameters in the metal inert gas (MIG) welding and laser beam welding (LBW) process in this study. The MIG welding and LBW are more welcomed welding methods due to their high efficiency and low cost. However, they are different as the LBW offers welding speed three to five times faster than MIG welding, while LBW’s heat transfer to workpieces is much less than MIG welding, which can avoid some distortions. The microstructure of zincalume steel (G550) was investigated using scanning electron microscopy (SEM) and the microstructure characterizations of welded specimens were analyzed. The experiment found the columnar dendrites extended under the heat flow direction during the MIG welding and LBW process. Thus, the columnar grains were formed in between the equiaxed zone and fusion zone (FZ) at high heat input and slow cooling rate. Moreover, the grain size of FZ was comparatively smaller than heat affected zone (HAZ) and base metal (BM).     

Research into Grinding Hardening of Microalloyed Non-quenched and Tempered Steel

Grinding hardening is a new technology of hardening steel piece surfaces with grinding heat generated in the grinding process instead of with a high or medium frequency induction heating method,which can effectively integrate grinding and surface hardening. Experimental studies were carried out on grinding hardening of non-quenched and tempered steel. Through grinding experiments with variable depths of cut and feeding rate,the variation in the depth of the hardening layer was studied and the microstructure of the hardening zone of the test pieces was subsequently ana-lyzed. In the end,the hardening effect of non-quenched and tempered steel was compared with that of 40Cr steel,which revealed the superiority of non-quenched and tempered steel in grinding hardening technology.     

TC4钛合金CO2激光焊接试验研究

根据TC4钛合金的焊接特点,设计和搭建用于钛合金激光焊接专用实验平台并进行实验室焊接试验。在TC4钛合金激光焊接过程中,应控制好焊前清理和做好等离子体控制等关键环节,并通过设计和安装惰性3路气体保护装置,得到合格的焊接接头.     

20CrMnTi钢激光焊接工艺与焊缝组织的研究

研究了激光焊接工艺参数对２０ＣｒＭｎＴｉ钢焊缝宏观形貌及其焊接接头组织的影响。通过金相组织分析，透射电镜观察以及硬度测试等研究结果表明，采用激光焊可以实现２０ＣｒＭｎＴｉ钢作为分体加工齿轮材料的深熔焊接，其热影响区较小，且可得到混合型马氏体组织。