基于SYSWELD的T型接头GMAW焊接热过程模拟及其应用

综合考虑GMAW熔滴过渡带入熔池的热焓量、余高以及相变潜热等因素,基于SYSWELD建立了T型接头GMAW焊接传热三维数学模型,并通过系列焊接工艺试验确定了焊接线能量对双椭球热源参数的影响规律。通过计算,获得了不同焊接热输入条件下JB800钢T型接头的焊缝几何参数,得到了焊接工艺条件对焊接热循环及其主要参数的影响规律。基于热过程模拟结果,借助JB800钢SH-CCT图,实现了对CGHAZ区组织、硬度预测和控制。另外,还进行了JB800钢T型接头焊接工艺试验,通过测试焊缝几何尺寸和热循环,并与计算结果比较,验证了模型的可靠性。     

16MnR、15MnVN及18MnMoNb钢焊接接头冲击疲劳寿命的试验研究

本文对常用低合金钢16MnR、15MnVN 以及18MnMoNb 钢及其焊接接头进行了小能量多次冲击对比试验,以分析焊接热循环对焊接接头多冲抗力(冲击疲劳寿命)的影响及变化规律。得出了不同冲击能量下,热影响区组织与焊接接头强度、塑性及韧性的规律关系。     

不锈钢高温合金氩弧焊电流探讨

通过电流大小对焊接接头的力学性能、裂纹敏感性、金相晶粒度和生产操作的影响试验,认为焊接不锈钢高温合金,采用较小的焊接电流和适宜的速度,或以较少的线能量输入,能获得高质量的焊接接头。     

X6CrNiTi18-10焊后热处理的工艺研究

通过选择焊接材料、焊接方法、工艺参数及热处理规范等对X6CrNiTi18-10奥氏体不锈钢进行焊后热处理的工艺试验研究。通过常温力学性能,焊接接头的微观金相组织分析了焊缝的强度及组织状态。最终试验结果表明工艺方案可行,可指导实际生产。     

双相不锈钢焊接接头耐蚀性的研究进展

简述了近年来对双相不锈钢焊接接头耐蚀性研究的进展及主要方向。主要介绍了异种焊接、特种焊接和传统焊接参数对双相不锈钢焊接接头耐蚀性的影响。大量的文献研究表明:接头处微观组织的变化、合金元素含量和第二相的析出均会对接头的耐蚀性造成影响。     

平台工艺管线用TP316L不锈钢焊接工艺研究

本文通过对TP316L不锈钢的焊接性进行分析,确定了采用的焊接方法、焊接材料及坡口形式等。通过焊接工艺试验,确定了该不锈钢的焊接工艺,最终获得了具有良好的力学性能和耐腐蚀性能的焊接接头。     

不锈钢复合板焊接接头晶间腐蚀失效分析

针对不锈钢复合板焊接接头出现晶间腐蚀裂纹问题,采用光学显微镜、扫描电镜、XRD等技术手段对复合板焊接接头的组织、成分以及相组成进行检测和分析,对焊接工艺规范和热处理制度对焊接接头耐蚀性的影响进行探讨。结果表明,接头焊缝区铁素体含量18．3％,晶粒度9．5级,过渡层焊缝铬的含量9．58％,低于耐蚀性要求;接头产生了σ等硬脆相,这些因素都增大晶间腐蚀敏感性;焊接线能量过大,将降低接头的腐蚀性能;复合板整体消应热处理可以取消。     

京、津、沪三市青工技术比赛 焊接比赛理论试题

~、是非题(坏题2分共18分,对了,错x) 1.手工电弧焊时,电源的挣特性曲线为水平段。() 2.焊接接头的机械性能试验包括:拉伸、弯曲、冲击和金相.() 3.如果焊件在焊接过程中产牛的压应力大于材料的屈服强度时,则焊后就不会产生焊接残余应力和残余变形.() 4.根据经验,当c:镇。.4%时,钢材的淬硬倾向不明显,可焊性优良,娜接时不必预热,() 5。在熔渣中加入c。P,,可以有效地改善其脱渣性。() 6。焊接线能量综合了焊条直径、焊接电流和电弧电压三个规范参数对焊接热循环的影响。() 7.由于酸性焊条药皮的脱氧性较强,所以焊缝金属的综合机械性能较核性…     

不锈钢焊接接头疲劳强度试验研究

通过焊接接头疲劳试验对SAF2 2 0 5双相不锈钢和 1Cr18Ni9Ti奥氏体不锈钢焊接接头S—N曲线进行详细分析 ,并与 16Mn钢焊接接头的试验结果进行比较 ,讨论不同材料焊接接头及试样接头型式对S—N曲线的影响。试验结果表明 ,SAF2 2 0 5钢和 1Cr18Ni9Ti钢焊接试样的常数m和N =2× 10 6疲劳强度与国际焊接学会 (IIW )推荐的数值有较大差异 ,采用IIW的S—N曲线对本文不锈钢焊接试样疲劳评定时 ,将给出偏于安全的结果 ;接头型式不同导致焊接接头局部应力集中有较大差异 ,因而对采用名义应力表示的S—N曲线有明显影响 ;在同类接头形式下 ,SAF2 2 0 5钢和1Cr18Ni9Ti钢焊接接头的焊态疲劳强度高于 16Mn钢焊接接头 ,而双相不锈钢接头具有更高的疲劳强度     

CAP1400蒸汽发生器压力边界焊接接头的显微组织

使用光学显微镜和扫描电镜研究了CAP1400蒸汽发生器压力边界焊接接头的显微组织,该压力边界焊接接头由SA508Gr.3Cl.2钢母材、热影响区、堆焊层和对接焊缝组成。结果表明:接头母材的显微组织为细小回火贝氏体,焊接热影响区的为粗大马氏体,不锈钢堆焊层的为柱状奥氏体和少量铁素体,镍基合金堆焊和对接焊缝的组织主要为柱状奥氏体;在多层多道焊接热循环作用下,不锈钢堆焊层和镍基合金对接焊缝中的奥氏体都发生了再结晶,奥氏体基体上有碳化物析出相。     

西气东输二线工程X80钢管半自动焊工艺研究

以西气东输二线工程用X80钢管为研究对象,通过焊接接头横向拉伸试验,焊缝和热影响区（HAZ）冲击韧性试验,焊缝和HAZ不同焊层显微组织分析,以及焊接接头不同焊层Hv10硬度试验等手段,研究了低氢型焊条根焊和自保护药芯焊丝半自动填充、盖面组合焊接工艺的环焊缝的焊接接头性能。试验结果表明,选择韧脆转变温度较低的自保护药芯焊丝、采用较小的焊接热输入量和多层多道的焊接措施等因素,对于保证X80钢管环焊接头的性能是至关重要的。采用低氢焊条根焊、自保护药芯焊丝半自动焊进行X80钢管焊接时,焊接接头的强度、-10℃低温冲击韧性和硬度等性能良好．该工萝应用于西气东输二线工程的焊接旆工是可行的．     

Effect of welding heat input on fatigue life of quenched boron steel and FB steel lap joint

The effect of welding heat input on the fatigue life of a quenched boron steel and ferrite-bainite (FB) steel lap joint was investigated. Boron steel was quenched and welded with FB steel in heat input ranging from 0.29 to 0.67 kJ/mm. Boron, which can increase hardenability, affected the microstructure and hardness of the weld metal and heat affected zone (HAZ). The hardness of the weld metal and HAZ increased with decreasing welding heat input, and the high hardness of the weld metal and boron steel HAZ prevented the initiation of cracks in the stress concentration area around the bead. The bead width increased with increasing heat input, and the results of finite element method (FEM) showed that the maximum stress in the notch of the weld joint decreased when the bead width was increased. That is to say, the fatigue life increased when the weld joint had wider bead width. Finally, while the fatigue life was affected by the residual stress, the variation of the welding heat input used in this study had hardly any affect on the residual stress distribution.     

Some investigations on microstructure and mechanical properties of submerged arc welded HSLA steel joints

This paper investigates the influence of the submerged arc welding (SAW) process parameters (welding current and welding speed) on the microstructure, hardness, and toughness of HSLA steel weld joints. Attempts have also been made to analyze the results on the basis of the heat input. The SAW process was used for the welding of 16 mm thick HSLA steel plates. The weld joints were prepared using comparatively high heat input (3.0 to 6.3 KJ/mm) by varying welding current (500–700 A) and welding speed (200–300 mm/min). Results showed that the increase in heat input coarsens the grain structure both in the weld metal and heat affected zone (HAZ). The hardness has been found to vary from the weld centre line to base metal and peak hardness was found in the HAZ. The hardness of the weld metal was largely uniform. The hardness reduced with the increase in welding current and reduction in welding speed (increasing heat input) while the toughness showed mixed trend. The increase in welding current from 500 A to 600 A at a given welding speed (200 mm/min or 300 mm/min) increased toughness and further increase in welding current up to 700 A lowered the toughness. Scanning electron microscopy of the fractured surfaces of impact test specimen was carried out to study the fracture modes. Electron probe micro analysis (EPMA) was carried out to investigate the variation in wt.% of different elements in the weld metal and HAZ.     

TP304不锈钢钢管环焊缝的A-TIG焊接研究

A-TIG焊接技术是基于TIG焊的焊接新工艺,具有大幅增加焊缝熔深、提高焊接生产率,降低成本等优点。本研究采用A-TIG焊接技术对TP304不锈钢50mm×6mm的管子进行全位置焊接,对得到的焊接接头进行射线探伤、显微组织分析以及力学性能测试,结果表明,接头的显微组织优于普通TIG焊接接头、接头质量和力学性能均达到标准要求。     

热输入对1 000 MPa级工程机械用钢接头组织性能的影响

采用三种热输入进行1 000 MPa级控轧控冷(Thermo mechanical control process, TMCP)高强钢的熔化极气体保护焊,利用金相显微镜、扫描电子显微镜和透射电子显微镜研究热输入对焊接接头组织和力学性能的影响。研究结果表明,三种热输入焊缝金属组织主要由板条马氏体和板条贝氏体为主、并含有少量残余奥氏体和粒状贝氏体;焊接热影响区粗晶区组织以板条马氏体和贝氏体为主,并含有少量粒状贝氏体。随着热输入的增加,焊缝组织中贝氏体板条粗化,马氏体板条减少,而粒状贝氏体逐渐增多,部分膜状残余奥氏体向块状转变;焊缝金属冲击韧度和硬度、接头强度逐渐降低,而接头热影响区冲击韧度先增后降;当热输入为15 kJ/cm时焊接接头强韧性匹配最佳。     

铁素体不锈钢CMT焊接接头HAZ组织性能研究

针对铁素体不锈钢焊接HAZ晶粒易长大的问题,提出采用小热输入的CMT焊接工艺。通过分析接头HAZ的显微组织、显微硬度和冲击性能,探讨了4003铁素体不锈钢焊接接头HAZ组织和性能,并与常规MIG焊焊接接头试样的组织、性能进行对比。试验结果表明:采用CMT焊接工艺获得的接头HAZ粗晶区宽度为460μm,明显窄于MIG焊接接头的粗晶区宽度545μm;CMT接头强度与MIG焊接接头显微硬度值相近,但CMT接头HAZ冲击韧性较MIG焊接接头试样提高了16.28%。     

Study of laser butt welding of SUS301L stainless steel and welding joint analysis

This paper describes a study on laser butt welding of 4 and 2 mm SUS301L stainless steel and a detailed analysis of welding joints. The gap tolerance of butt joint was also studied with optimized process parameters. The electrolytic etching in 10 % oxalate solution was used to test the intergranular corrosion of the 4 mm SUS301L welded joint. Fatigue property of the 2 mm SUS301L welded joint was tested under the conditional cycle times of 1?×?10⁷. Using optical microscopy, the changes of metallurgical microstructure in the weld zone of 4 mm SUS301L were also studied. It has been found that laser butt welding of 4 mm SUS301L is able to achieve sound metallurgical morphology and high strength weld joint when the butt gap is within certain tolerance. The weld joint also has good resistance to intergranular corrosion and has a fatigue limit of 310 MPa.     

等离子弧焊焊接尿素合成塔不锈钢衬里的试验研究

通过对焊接接头的化学成分分析、力学性能试验、晶间腐蚀、选择性腐蚀试验和金相检查,证明等离子弧焊可以用于焊接尿素合成塔的尿素级不锈钢衬里,且效率高、焊接质量稳定,建议将该焊接方法纳入相关规范和工程设计标准加以使用。     

Evaluation on microstructure and mechanical properties of high-strength low-alloy steel joints with oscillating arc narrow gap GMA welding

Abstract with the purpose of improving weld joint quality and productivity, the oscillating arc narrow gap gas metal arc (GMA) welding was employed in welding quenched and tempered high-strength low-alloy thick steel. The microstructure and mechanical properties of weld joints were evaluated, namely micro-hardness, tensile strength, and low-temperature impact toughness. The test results indicated that mechanical properties of weld joints with oscillating arc narrow gap GMA welding were excellent and found to meet stipulated requirements. Oscillating arc narrow gap GMA welding is a promising process for welding quenched and tempered HSLA thick steels due to the low energy input and narrow square-butt groove.     

Some studies on temperature profiles in AISI 304 stainless steel sheet during laser beam welding using FE simulation

The investigation of transient temperature profiles of a weld joint produced by the laser welding process is presented. A three-dimensional finite element model is developed using a commercial finite element code ANSYS in order to obtain the behavior of temperature field and molten pool shape during the welding process. A three-dimensional conical Gaussian heat source is employed as a heat source model for performing a non-linear transient thermal analysis. The temperature-dependent material properties of AISI 304 stainless steel sheet are taken into account, which has a great influence on the temperature fields indicated by the simulation results. The effect of latent heat and the convective and radiative boundary conditions are also included in the model. A series of laser welds are performed using a 2-kW continuous wave Nd:YAG laser welding system. The experimental trials are conducted by varying the laser input parameters namely beam power, welding speed, and beam incident angle to validate the model. The results show that there is a good agreement between the finite element simulation and the experimental observations.