共查询到20条相似文献,搜索用时 31 毫秒
1.
氮对316L不锈钢焊缝力学性能的影响 总被引:2,自引:0,他引:2
为研究氮对316L不锈钢焊缝力学性能的影响,采用不同氮质量分数的三种自行研制的焊丝,分别对几组316L不锈钢试板进行钨极氩弧焊(Tungsten inert gas,TIG)焊接,焊后通过金相显微镜和扫描电镜分别观察并分析相应的焊缝组织,采用磁性法测量焊缝的铁素体的质量分数,并对焊缝的拉伸性能、冲击性能等力学性能进行测试。从氮的固溶和焊缝组织的变化等方面综合分析氮对316L不锈钢焊缝力学性能的影响。结果发现,随着氮质量分数的增加,焊缝奥氏体组织明显粗化,铁素体质量分数呈下降趋势;焊缝强度有所提高,且氮质量分数由0.011%增加到0.081%时焊缝强度的平均提高程度小于氮质量分数由0.081%增加到0.10%时焊缝强度的平均提高程度;另外,焊缝的塑性及冲击韧度均有所降低。 相似文献
2.
Ramazan Yılmaz Mustafa Tümer 《The International Journal of Advanced Manufacturing Technology》2013,67(5-8):1433-1447
In this study, AISI 316 L austenitic stainless steel and AH36 low-alloy ship building steel pair were joined with flux-cored arc welding method by using E309LT1-1/4 filler metal under four different shielding gas compositions containing CO2 at different ratios. Microstructure, impact toughness of welded materials, and their microhardness distribution throughout joining were determined. In macro- and microstructure examinations, stereo optical microscope, scanning electron microscope (SEM), SEM/energy dispersive spectroscopy, and SEM/mapping analysis techniques were used. After notched impact toughness, fracture surfaces were examined using the scanning electron microscope. This study investigated effects of shielding gas composition on microstructure, impact toughness, and microhardness distribution of transition zone between AH36 steel and weld metal of joined material. It is observed that based on an increase in amount of CO2 in shielding gas, impact toughness values of the weldment decreased. Microhardness values change throughout weld metal depended on shielding gas composition. Moreover, an increase in amount of CO2 within shielding gas decreased δ-ferrite amount in weld metal. The increase in amount of CO2 within shielding gas leads to expanded transition zone in interface between AH36 and weld metal and also affects notched impact toughness values negatively due to the inclusion amounts occurring in weld metal and hence caused it to decrease. 相似文献
3.
Evaluation on microstructure and mechanical properties of high-strength low-alloy steel joints with oscillating arc narrow gap GMA welding 总被引:1,自引:0,他引:1
W. H. Xu S. B. Lin C. L. Fan C. L. Yang 《The International Journal of Advanced Manufacturing Technology》2014,75(9-12):1439-1446
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. 相似文献
4.
Effect of shielding gas mixture on gas metal arc welding of HSLA steel using solid and flux-cored wires 总被引:1,自引:0,他引:1
S. Mukhopadhyay T.K. Pal 《The International Journal of Advanced Manufacturing Technology》2006,29(3-4):262-268
In this work, gas metal arc welding of high strength-low alloy (HSLA) steel with solid- and flux-cored arc welding wires using
different shielding gas compositions was performed. The composition of filler wire and shielding gas in gas metal arc welds
of HSLA steel determines the inclusion characteristics, microstructure and mechanical properties. Thus, acceptable weld metal
properties in HSLA steel using gas metal arc welding (GMAW) process could be achieved with the proper combination of filler
wire and shielding gas composition. 相似文献
5.
Mohammad Hosein Bina Mostafa Jamali Morteza Shamanian Hamed Sabet 《The International Journal of Advanced Manufacturing Technology》2014,75(9-12):1371-1379
In this work, the effect of weld current on joining capability of austenitic stainless steel (AISI 304) and ferritic stainless steel (AISI 430) sheets with application of resistance spot welding process was investigated. Macrostructure, microstructure, microhardness, tensile shear strength, and failure mode of welded materials were evaluated for different weld currents. The values of weld current were 2.5, 3.75, and 5 kA. It was found that when the weld current increased, the nugget size and the weld strength were increased. Two distinct failure modes including interfacial and pullout were observed during tensile shear test. Finally, an adequate weld current was obtained. 相似文献
6.
在激光-MAG复合焊中,金属蒸气和背部熔池包含着大量的焊接状态信息。以316不锈钢和400低碳钢为试验对象,作异种材料复合焊接,并应用高速摄像机获取焊接过程中正面金属蒸气和背部熔池的实时图像。提取金属蒸气面积形态特征,结合背部熔池图像同步分析金属蒸气周期性变化规律并研究金属蒸气和焊接状态、焊缝成形之间的关系。以灰度共生矩阵(GLCM)方法分析图像纹理特征,并用能量、对比度和熵三个特征分析背部熔池与焊缝成形之间的关系。结果表明,所分析方法能有效反映金属蒸气的变化机理,金属蒸气和背部熔池与焊接状态之间的关联,为在线检测复合焊接质量提供依据。 相似文献
7.
Giuseppe Casalino Sabina Luisa Campanelli Antonio Domenico Ludovico 《The International Journal of Advanced Manufacturing Technology》2013,68(1-4):209-216
Selective laser melting (SLM) is a successful tool-free powder additive technology. The success of this manufacturing process results from the possibility to create complex shape parts, with intrinsic engineered features and good mechanical properties. Joining SLM steel to similar or dissimilar steel can overcome some limitations of the product design like small dimension, undercut profile, and residual stress concentration. In this way, the range of applications of the SLM process can be broadened. In this paper, the hybrid laser welding of selective laser molten stainless steel was investigated. A high-power fiber laser was coupled to an electric arc and austenitic stainless steel wrought and SLM parts were welded together. The power and speed parameters were investigated. The joints were analyzed in terms of weld bead profile, microstructure, microhardness, and tensile test. The efficiency of the welding process was evaluated through the line energy input versus the weld molten area. 相似文献
8.
Gaurav Sharma D. K. Dwivedi 《The International Journal of Advanced Manufacturing Technology》2017,88(5-8):1299-1307
In the present study, microstructure and mechanical properties of dissimilar weld of structural steel and ferritic stainless steel (FSS) plates of thickness 3 mm were investigated. The plates were butt welded by friction stir welding and defect-free welds were produced at a traverse speed of 20 mm/min and rotational speed of 508 rpm using a tungsten carbide tool. The weld joint consisted of alternate bands of both steels resembling an onion ring pattern. In the weld joint, six distinct regions were found including both the base metals. The stir zone of structural steel revealed refined grain structure of ferrite, pearlite, and martensite whereas in ferritic stainless side, highly refined ferritic grains with grain boundary martensite was observed and also confirmed by x-ray diffraction (XRD). The hardness of the weld joint varies from 186 to 572 HV. This scatter of hardness in stir zone is due to the presence of metal from both sides. The ultimate tensile and yield strengths of the transverse weld specimens was higher than the structural steel base metal whereas lower than the ferritic stainless steel, having fracture from structural steel side. 相似文献
9.
Effect of surface tension metal transfer on fume formation rate during flux-cored arc welding of HSLA steel 总被引:1,自引:1,他引:0
K. Srinivasan V. Balasubramanian 《The International Journal of Advanced Manufacturing Technology》2011,56(1-4):125-134
This paper reports the effect of process parameters on fume formation rate during flux-cored arc welding (FCAW) of high-strength low-alloy (HSLA) steel plates using steady current mode and surface tension transfer (STT) mode. Five levels of wire feed speed and five levels of voltage were used to generate welding fumes. Fume formation rate (FFR) was determined by ANSI/AWS F1.2 method. Investigation reveals that FCAW with STT mode reduced the FFR around 40?C50% when compared with steady current mode. The STT mode of welding also provides excellent weld bead geometry and microhardness level. Three-dimensional representation of FFR was generated and gives clear representation about the influence of process parameters on FFR for both the steady current mode and STT mode welding. 相似文献
10.
用于制造高参数压力容器的低合金高强度铜采用窄间隙埋弧焊,为了消除焊接残余应力,在焊后需对焊接接头进行热处理,其冲击韧性大幅下降。为探讨其脆化机理,选用BHW-35钢为母材,H10Mn2NiMoA镀铜焊丝和SJ101焊剂为填充材料,焊后热处理工艺为920℃正火+620℃和560℃二次回火。利用扫描透射电镜,对焊缝熔敷金属焊态和焊后热处理的显微组织变化进行了研究。结果表明,低合金高强度钢焊缝焊态时组织为针状铁素体,在晶内有细小碳化物弥散分布;经焊后热处理,由于回复作用板条状组织变粗或消失,在晶界磷元素的偏聚和大量的碳化物在晶界析出导致其冲击韧性下降。窄间隙埋弧焊是一种优质高效的焊接方法,焊接效率高,节约焊材,解决了大厚度工件焊接的技术问题。 相似文献
11.
Most research to date concerning the cryogenic toughness of austenitic stainless steels has concentrated on the base metal and weld metal in weldments. The most severe problem faced on the conventional austenitic stainless steel is the thermal aging degradation such as sensitization and carbide induced embrittlement. In this paper, we investigate the cryogenic toughness degradation which can be occurred for austenitic stainless in welding. The test materials are austenitic stainless JN1, JJ1 and JK2 steels, which are materials recently developed for use in nuclear fusion apparatus at cryogenic temperature. The small punch (SP) test was conducted to detect similar isothermally aging condition with material degradation occurred in service welding. The single-specimen unloading compliance method was used to determine toughness degradation caused by thermal aging for austenitic stainless steels. In addition, we have investigated size effect on fracture toughness by using 20% side-grooved 0.5TCT specimens. 相似文献
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13.
采用微拉伸试验研究了CrMoV钢焊接接头焊缝金属的局部力学性能,并对焊缝金属进行了微观组织观察和显微硬度测试。结果表明,焊缝金属呈现不均匀的微观组织分布;焊缝金属环向试样的拉伸强度要大于径向和轴向试样的拉伸强度,而焊缝中心所取试样的拉伸强度要小于焊道上所取试样的拉伸强度。结合金相分析得到,焊接接头焊缝金属最薄弱的部位在焊缝中心等轴晶区。 相似文献
14.
采用自主研制搅拌针长度为8.5mm的静止轴肩搅拌工具和2A14-T4厚板铝合金进行150°角焊缝接头静止轴肩搅拌摩擦焊工艺试验,探讨焊接工艺参数对接头组织和力学性能的影响规律。结果表明:在500~700r/min主轴转速与40~100mm/min焊接速度范围内均可获得表面光滑无内部缺陷的角焊缝接头,其外观尺寸可精确控制基本无残余焊接角变形。焊缝区主要由焊核(Stir zone,SZ)组成,SZ形状类似搅拌针圆锥台状或椭圆状、其宽度沿厚度方向分布比较均匀;热力影响区(Thermal mechanical affected zone,TMAZ)及热影响区(Heat affected zone,HAZ)宽度明显较小。焊缝区硬度分布具有明显不均匀特征,最薄弱区位于TMAZ与HAZ的交界处。主轴转速变化对焊缝区平均硬度影响较小,但随着焊接速度增加其平均硬度明显增大。角焊缝前进侧等效拉伸强度大于后退侧,等效拉伸强度随转速增加而减小,焊速的增大而增大。在500r/min-100mm/min焊接工艺下所得到的接头等效拉伸强度最高,可达到母材的79.24%。在拉-剪复合承载模式下,角焊缝拉伸试样宏观塑性变形很小呈现脆性断裂特征。 相似文献
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A. K. Lakshminarayanan V. Balasubramanian G. Madhusudhan Reddy 《The International Journal of Advanced Manufacturing Technology》2011,55(1-4):153-162
This paper deals with the microstructure and mechanical characterization of electron beam-welded AISI 409M-grade ferritic stainless steel joints. Single-pass autogenous welds free of volumetric defects were produced at a welding speed of 1,000?mm/min. The joints were subjected to optical microscopy, scanning electron fractography, microhardness, transverse and longitudinal tensile, bend and charpy impact toughness testing. The coarse ferrite grains in the base metal were changed into fine equiaxed axial grains and columnar grains as a result of characteristic rapid solidification of electron beam welds. Tensile testing indicates overmatching of the weld metal relative to the base metal. The joints exhibited acceptable impact toughness and bend strength properties. 相似文献
18.
Rajesh Manti D. K. Dwivedi A. Agarwal 《The International Journal of Advanced Manufacturing Technology》2008,36(3-4):263-269
This paper describes the effects of pulsed TIG welding process parameters (pulse duration, peak current, and pulse frequency)
on the microstructure and microhardness of Al-0.8%Mg-0.5%Si (6061) alloys. It was observed that pulse TIG welding produced
finer grain structure of weld metal than conventional TIG welding (without arc pulsation). An increase in the pulse frequency
has been found to refine the aluminium and eutectic grain structure of weld metal especially when welding is done using short
pulse duration. Long pulse duration lowers the pulse frequency up to which refinement of constituents in weld metal takes
place. Effect of the pulse frequency on the grain structure was found to be determined by pulse duration. For a given pulse
frequency, long pulse duration produced a coarser structure than short pulse duration. An increase in the peak current coarsened
the grain structure. 相似文献
19.
Chang Hee Suh Rac Gyu Lee Sang Kyun Oh Yun-Chul Jung Je-Young Son Young Suk Kim 《Journal of Mechanical Science and Technology》2011,25(7):1727-1735
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. 相似文献
20.
选取一组优化的焊接参数对2205双相不锈钢板进行药芯焊丝CO2气体保护焊,对比研究了焊缝和母材的显微组织和耐腐蚀性能。结果表明:焊缝与母材均由铁素体和奥氏体两相组织组成,且铁素体体积分数相近,分别为42.4%,49.5%;在FeCl3溶液中浸泡腐蚀时,随着FeCl3溶液浓度的增大和温度的升高,焊缝及母材的点腐蚀速率均增大,且焊缝的点腐蚀速率高于母材的,说明焊缝的耐点腐蚀性能更差;焊缝的自腐蚀电位、容抗弧半径、钝化膜电阻均低于母材的,说明焊缝的耐电化学腐蚀性能更差,但焊缝腐蚀时形核阻力较大,腐蚀坑不易扩展。 相似文献