数控激光焊接汽车用高强钢工艺参数的优化

在CO2激光焊接加工中,影响高强镀锌钢板焊接质量的因素很多。根据试验加工对相关因素进行了分析,并给出了一套可以有效控制焊接高强钢加工质量的优化工艺参数,从而确保汽车用高强铜的焊接质量。     

车用高强钢的激光焊接

本文论述了超高强钢（UHS）薄板焊接工艺的进展,焊接采用光纤传输固态激光器,确定了焊缝的强度和成形性能。采用三种不同的光纤传输固态激光器对厚度0．8～1．5mm、拉伸强度600～1550MP＆、同种材料和不同材料组合的双相钢（DP）、相变诱发塑性钢（TRIP）、Usibor钢和硼钢进行自发二氧化碳激光焊接试验,以获得穿透的对接搭接双相焊缝。确定了熔合区和热影响区的硬化、软化行为．还分析了激光工艺参数对焊接速度、焊缝形貌及接头性能的影响。     

DOGAL 800DP镀锌高强钢数控C02激光焊接工艺参数的优化

采用正交方法优化试验方案,对DOGAL 800DP镀锌高强钢进行激光焊接试验,并对激光焊接试样进行了多种焊接质量的检测.结果表明:数控CO2激光焊接1.5 mm厚镀锌高强钢时,在试验条件下保证焊缝成形、强度和质量的优化工艺参数是以氮气作为保护气体,同轴气流量为3.0 m3·h-1,激光功率1300 W,离焦量-0.4 mm,焊接速度0.80 m·min-1,侧吹气流与水平方向成40°夹角,侧吹气流量2.1 m3·h-1.     

DOGAL 800DP镀锌高强钢数控CO_2激光焊接工艺参数的优化

采用正交方法优化试验方案,对DOGAL 800DP镀锌高强钢进行激光焊接试验,并对激光焊接试样进行了多种焊接质量的检测。结果表明:数控CO2激光焊接1.5 mm厚镀锌高强钢时,在试验条件下保证焊缝成形、强度和质量的优化工艺参数是以氮气作为保护气体,同轴气流量为3.0 m3.h-1,激光功率1 300 W,离焦量-0.4 mm,焊接速度0.80 m.min-1,侧吹气流与水平方向成40°夹角,侧吹气流量2.1 m3.h-1。     

HG980D高强钢焊接试验研究

我公司是当今世界最大的液压支架生产基地。随着煤炭行业的快速发展,液压支架的重量和工作阻力也越来越大,因此对液压支架的重要部件推杆的强度要求也越来越高。在这样的背景下,我公司和武钢共同开发了低合金高强度钢HG980D,屈服强度达到900MPa级,专门用于高端液压支架推杆的生产制造。为了掌握该钢种的基本焊接性,合理优化焊接工艺,使HG980钢的焊接接头性能能够满足液压支架井下较苛刻的工况,我公司对HG980D钢板的冷裂纹敏感性、焊接工艺、焊后热处理工艺及焊接接头综合力学性能进行了试验研究。     

汽车用高强度钢的激光焊焊接性研究

激光焊接汽车用高强度钢主要利用激光的热循环特点,加热冷却速度快,可细化高强度钢焊接接头处的晶粒,但仍然存在裂纹、软化、降低疲劳强度及耐磨性问题。通过一些试验,分析了激光焊接后接头的一些特性,从而肯定激光焊接的可行性。     

激光焊接接头的质量控制研究

激光焊接高强度镀锌钢时,采用引弧板和接弧板的方法,可以避免不稳定的熔宽变化造成的不良影响。由于激光焊接时工件表面镀锌层的蒸发而影响接头的耐蚀性,为此采用浓度为3%的盐水对不同激光焊接工艺的焊接件进行腐蚀试验,获得了腐蚀前后的焊接接头的质量变化量和金相图。研究表明,在不同工艺参数的条件下,激光焊接高强度镀锌钢焊接接头的腐蚀速度不同,其平均速度与母材的腐蚀速度大体相当,不会影响接头的抗腐蚀性能。     

激光焊接对汽车车身质量的影响

随着激光焊接技术的发展,激光焊接技术应用的领域越来越广。近年来,激光焊接技术在汽车车身制造上得到了充分运用,充分发挥了其低成本、高质量的特点,有效地提高了车身质量。为了提升我国汽车在国际市场上的竞争力,就必须加大对激光焊接技术在车身制造方面的研究,不断提升我国汽车的车身质量和整车质量。     

影响高破片率钢焊接表面缺陷磁粉探伤检测质量的研究

由于高强钢的焊接特性,往往在实际生产中出现裂纹等表面缺陷.磁粉检测被认为是表面裂纹检测最灵敏的方法之一,尤其是在表面不平或表面不规则性与所需检测的裂纹相比大得多的情况下,磁粉探伤通常被考虑为表面裂纹检测最好的方法.通过表面缺陷磁粉探伤原理,对磁粉探伤的磁痕特性.磁痕形成受到磁粉性能、磁化规范、磁悬液的浓度和黏度、零件表面状况、裂纹形状等因素的影响进行分析.为提高焊缝磁粉探伤检测质量,操作中需要综合考虑这些因素,以便于使工件的表面缺陷经磁化形成的磁痕能清晰地显示出来而且能被准确地予以判断,提高表面缺陷检测准确性.     

镀锌高强钢激光深熔焊接温度研究

通过对薄板激光深熔焊接焊缝形状的研究,建立了薄板深熔焊接点线叠加的热源模型.通过对比数值计算和试验测定的焊件表面不同点处温度,验证了理论模型的正确性,为激光薄板焊接优化工艺参数提供依据.     

A304不锈钢薄板激光焊接的光谱分析

为了进一步分析不同焊接参数对A304不锈钢薄板激光焊接效果的影响,该文在不同的焊接参数和激光输出方式下,采用AvaSpec-2048型光纤光谱仪对A304不锈钢薄板激光焊接的电弧进行了光谱分析。研究结果表明,激光功率、焊接速度和激光输出方式对激发出特征谱线的元素的种类和激光等离子体中元素的含量有一定的影响。     

焊接材料质量信息的智能化判读

为了在线判读弧焊焊接过程的质量信息,开发了焊接电流、电弧电压信号采集和分析系统.     

Structure and performance of welding joint of Q235 steel welded by SHS welding

A self-propagating high-temperature synthesis (SHS) welding-pen that can weld steel workpiece from 6 to 10 mm is developed and welds the Q235 steel. The structure and properties of the welding joint are studied. The result indicates that this type of welding is melting and the fusion zone is clear. The tensile-strength of the welding joint is 283 MPa, flexural strength is 628 MPa, impact toughness is 46.43 J·cm⁻², and the microhardness of the welding joint and fusion zone are 230 HV_0.1 and 255.6€HV_0.1, respectively. The mircohardness of the fusion zone and the welding line are higher than that of the matrix.     

Effects of laser shock processing on mechanical properties of laser welded ANSI 304 stainless steel joint

With the rapid development of engineering component with integration,high-speed and multi-parameter,traditional techniques haven’t met practical needs in extreme service environment.Laser welding,a new welding technology,has been widely used.However,it would generate the drop of mechanical properties for laser welded joint due to its thermal effect.Laser shock processing(LSP) is one of the most effective methods to improve the mechanical properties of laser welded ANSI 304 stainless steel joint.In this paper,the effects of LSP on the mechanical properties of laser welded ANSI 304 stainless steel joint have been investigated.The welded joint on the front of the tensile samples is treated by LSP impacts,and the overlapping rate of the laser spot is 50%.The tensile test of the laser welded joint with and without LSP impacts is carried out,and the fracture morphology of the tensile samples is analyzed by scanning electron microscope(SEM).Compared with the yield strength of 11.70 kN,the tensile strength of 37.66 kN,the yield-to-tensile strength ratio of 0.310 7,the elongation of 25.20%,the area reduction of 32.68% and the elastic modulus of 13 063.876 MPa,the corresponding values after LSP impacts are 14.25 kN,38.74 kN,0.367 8,26.58%,42.29% and 14 754.394 MPa,respectively.Through LSP impacts,the increasing ratio of the yield strength and tensile strength are 121.79% and 102.87%,respectively;the elongation and area reduction are improved by 5.48% and 29.38%,respectively.By comparing with coarse fracture surface of the welded joint,the delamination splitting with some cracks in the sharp corner of the welded joint and asymmetric dimples,LSP can cause brighter fracture surface,and finer and more uniform dimples.Finally,the schematic illustration of dimple formation with LSP is clearly described.The proposed research ensures that the LSP technology can clearly improve the yield strength,tensile strength,yield-to-tensile strength ratio,elongation,area reduction and elastic modulus of the welded joint.The enhancement mechanism of LSP on laser welded ANSI 304 stainless steel joint is mainly due to the fact that the refined and uniform dimples effectively delay the fracture of laser welded joints.     

数控车床的机械结构分析

介绍了数控机床的技术特点，分析了数控车床的组成结构，并阐述了每种结构的特点。     

焊接质量控制浅论

分析影响焊接质量的主要因素，并针对焊接中存在的问题提出了解决办法。加强质量控制可以有效地提高焊接质量降低生产成本。     

CO2 laser welding of interstitial free galvanized steel sheets used in tailor welded blanks

Recently, laser welding technologies have been widely utilized to weld different automobile panels. In this research, the laser beam welding (LBW) process of interstitial free (IF) steel sheets used in the manufacturing of the car body was investigated on the basis of mathematical models. The quality indexes of LBW joints were estimated from Erichsen Cupping Test results including strength and Erichsen Cupping Index. Furthermore, three process parameters, namely laser power (P), welding speed (S), and focal position (F) were considered as the factors influencing the quality indexes. A 2.2-kW CO₂-laser beam was utilized to weld 1.2- and 0.8-mm-thick IF steel sheets. The modeling is done using experimental data which were gathered using design of experiments approach based on central composite face centered design matrix. The final regression models can be used to predict the quality indexes of laser beam-welded IF steel sheets joints at 95% confidence level. Optical metallography was utilized to characterize the weld profile and microstructures. In the second phase of this research, multi-objective genetic algorithm with the fitness function based on regression models was employed as an optimization procedure; as a result, the best quality indexes were obtained. Optimization results showed high compatibility with the actual experimental data.     

Research on overlaying welding rod of high hardness maraging steel

The development of new maraging steel overlaying welding rod, which contains Co, Mo, W and V alloy, solved the problems of poor homogeneity of hardness and mechanical process, prolonged the service life of wear-resistant components and increased the productive efficiency of repairing, greatly benefiting the national economy. __________ Translated from China Surface Engineering, 2006, 19 (3) (in Chinese)     

Processing parameter optimization of fiber laser beam welding using an ensemble of metamodels and MOABC

In fiber laser beam welding (LBW), the selection of optimal processing parameters is challenging and plays a key role in improving the bead geometry and welding quality. This study proposes a multi-objective optimization framework by combining an ensemble of metamodels (EMs) with the multi-objective artificial bee colony algorithm (MOABC) to identify the optimal welding parameters. An inverse proportional weighting method that considers the leave-one-out prediction error is presented to construct EM, which incorporates the competitive strengths of three metamodels. EM constructs the correlation between processing parameters (laser power, welding speed, and distance defocus) and bead geometries (bead width, depth of penetration, neck width, and neck depth) with average errors of 10.95%, 7.04%, 7.63%, and 8.62%, respectively. On the basis of EM, MOABC is employed to approximate the Pareto front, and verification experiments show that the relative errors are less than 14.67%. Furthermore, the main effect and the interaction effect of processing parameters on bead geometries are studied. Results demonstrate that the proposed EM-MOABC is effective in guiding actual fiber LBW applications.     

CF62低合金高强度钢在严寒地区汽车车架上的应用

研究了CF62低合金高强度钢的机械性能和可焊性，并采取措施对CF62钢的焊接质量进行控制结果表明，其焊缝成形美观，机械性能、低温韧性和焊接性能基本满足严寒地区用汽车车架的要求。