Resistance spot welding

حرية الوصول المقاله

1 - Evaluation of Performance of Resistance Spot Welded Joints with Different Parameters in Advanced High Strength TRIP Steel
I. Hajiannia R. Ashiri M. R. Pakmanesh M. Shamanian M. Atapour

In this research, ultrahigh strength transformation induced plasticity-assisted steel (TRIP-assisted steel) was developed to be used in the automobile body. For this, it is essential to characterize its weldability in resistance spot welding process. Therefore, the resi أکثر

In this research, ultrahigh strength transformation induced plasticity-assisted steel (TRIP-assisted steel) was developed to be used in the automobile body. For this, it is essential to characterize its weldability in resistance spot welding process. Therefore, the resistance spot welding metallurgy and weldability of the steel under different welding parameters are studied. the desired sample was studied in two states with higher pressure and less time. The results are presented following the most important advantage of the current steel in contrast to the similar steels is its excellent weldability enabling its application in the auto pillar. The microstructure and mechanical properties of TRIP steel spot welds were characterized using metallurgical techniques, lap shear tensile tests fractography and microhardness testing methods. Failure mode transition from interfacial to pullout failure mode was achieved for sample 10kA with 4kN. Partial interfacial failure was removed after nugget size increased. Pullout failure mode is seen for the sample 2, 10kA with 3.5kN. تفاصيل المقالة

حرية الوصول المقاله

2 - An Experimental Investigation on Comparison of the Similar and Dissimilar Resistance Spot Welding of St12 and Galvanized Steel using Design of Experiments
Mahmoud Moradi Hadi Abdollahi Ali Khorram

In the present research, similar and dissimilar resistance spot welding (RSW) process of St12 and galvanized steel sheets with thickness of 0.9 mm was investigated. The experiments were carried out based on the statistical design of experiments (DOE) approach to investi أکثر

In the present research, similar and dissimilar resistance spot welding (RSW) process of St12 and galvanized steel sheets with thickness of 0.9 mm was investigated. The experiments were carried out based on the statistical design of experiments (DOE) approach to investigate the effect of RSW parameters on the welding quality, achieving the mathematical regression equations and predicting the new results. Welding time and electrode force were considered as the input process variables while the tensile-shear strength of the joints was considered as the process response. By comparing three RSW types, galvanized steel has the highest tensile-shear strength. Statistical analysis shows that tensile-shear strength is increased with increasing electrode force and welding time. Verification experiments for three types of RSW joints were carried out in order to analyse the obtained results via software. Good agreement between the verification tests and the optimization results revealed that the statistical modelling would be appropriate for RSW process. Welding time (T)  = 5 s and electrode force (P)  = 925 N, welding time (T) = 5 s and electrode force (P) = 1100 N and welding time (T) = 3 s and electrode force (P) = 925 N were obtained as the optimum settings for similar RSW of St12, dissimilar RSW of St12 to galvanized steel and similar RSW of galvanized steel, respectively. تفاصيل المقالة

حرية الوصول المقاله

3 - Dissimilar resistance spot welding of AISI 1075 eutectoid steel to AISI 201 stainless steel
Mehdi Safari Hossein Mostaan

In this paper, dissimilar resistance spot welding of AISI 1075 eutectoid steel to AISI 201 stainless steel is investigated experimentally. For this purpose, the experiments are designed using response surface methodology and based on four-factor, five-level central comp أکثر

In this paper, dissimilar resistance spot welding of AISI 1075 eutectoid steel to AISI 201 stainless steel is investigated experimentally. For this purpose, the experiments are designed using response surface methodology and based on four-factor, five-level central composite design. The effects of process parameters such as welding current, welding time, cooling time and electrode force are investigated on the tensile-shear strength of resistance spot welds. The results show that tensile-shear strength of spot welds is increased with increase in the welding current and welding time. Also, it is concluded from results that with increasing the electrode force and cooling time, tensile-shear strength of welded joints is decreased. During tensile-shear tests, three failure modes are observed, namely interfacial, partial pullout and pullout modes. The analysis of variance for the tensile-shear strength indicates that the main effects of welding current, electrode force, welding time, cooling time, second- order effect of the welding current and cooling time, two level interactions of welding current with welding time, welding current with cooling time and electrode force with cooling time are significant model terms. The results of analysis of variance show that the presented model for tensile-shear strength of dissimilar resistance spot welds of AISI 1075 eutectoid steel to AISI 201 stainless steel can predict 95.00% of the experimental data and leave only 5.00% of the total variations as unexplained. تفاصيل المقالة

حرية الوصول المقاله

In this research, microstructure and mechanical performance of dissimilar resistance spot welded DP780/DP980 dual-phase steels were studied utilizing optical microscope, microhardness, and tensile shear tests. Resistance spot welding (RSW) was performed in the current r أکثر

In this research, microstructure and mechanical performance of dissimilar resistance spot welded DP780/DP980 dual-phase steels were studied utilizing optical microscope, microhardness, and tensile shear tests. Resistance spot welding (RSW) was performed in the current range of 7 to 12 kA, with 0.5 kA steps. At welding currents lower than 7 kA low amount of melting led to the very low strength of the joints due to small weld nugget diameter. The results showed that an increase in welding current from 7 kA up to 11 kA, result in an increase in weld nugget diameter. Further increase of welding current (higher than 11 kA), however decreased the weld nugget diameter due to severe melt expulsion. Microstructural studies showed that weld nugget was primarily comprised of martensite, and the heat-affected zone (HAZ) of both sides of the joint was comprised of three different microstructural zones; upper-critical HAZ (UCHAZ), inter-critical HAZ (ICHAZ), and sub-critical HAZ(SCHAZ). Microhardness test showed that at both sides, softening occurred at SCHAZ. The results of the tensile shear test showed that both peak load and fracture energy of the joints followed approximately the same trend as weld diameter with welding current. Two different fracture modes of interfacial failure (IF) and pullout failure (PF) were observed in the tensile-shear test. At welding currents lower than 10 kA, the failure occurred in IF mode, while at higher welding currents, PF was dominant. Weld nugget diameter at welding current of 10 kA; i.e., critical weld nugget diameter, was ~8.5 mm. تفاصيل المقالة

حرية الوصول المقاله

5 - بررسی تجربی و بهبود استحکام جوش مقاومت نقطه‌ای در لامپ‌های هالوژن به روش آماری تاگوچی
لطفعلی مظفری وانانی صادق رحمتی

جوشکاری مقاومتی نقطه‌ای کاربرد زیادی در صنعت و به خصوص در ساخت بدنه و برخی قطعات خودرو دارد. همچنین از روش جوشکاری مقاومتی در تولید لامپ‌های هالوژن خودرو نیز استفاده می‌شود. در این تحقیق، با هدف بهینه سازی راندمان خط تولید و نیز بهبود استحکام جوش مقاومت نقطه‌ای لامپ‌های أکثر

جوشکاری مقاومتی نقطه‌ای کاربرد زیادی در صنعت و به خصوص در ساخت بدنه و برخی قطعات خودرو دارد. همچنین از روش جوشکاری مقاومتی در تولید لامپ‌های هالوژن خودرو نیز استفاده می‌شود. در این تحقیق، با هدف بهینه سازی راندمان خط تولید و نیز بهبود استحکام جوش مقاومت نقطه‌ای لامپ‌های خودرو، بررسی‌های تجربی روی عوامل موثر بر استحکام جوش دو قطعه وینگ(Wing) به بادی(Body) در لامپ‌های هالوژن H4 (نوربالا-پایین) خودرو انجام شده است. فرایند طراحی آزمایش‌ها و تحلیل نتایج به روش تاگوچی و با کمک نرم‌افزار Minitab صورت گرفت. میزان تاثیر عواملی همچون جریان جوش، زمان و جنس الکترود جوشکاری در نمونه‌های واقعی لامپ بررسی شد. نتایج آزمایش‌ها و تحلیل‌های آماری حاکی از وابستگی بالای استحکام جوش به زمان در درجه اول و با اختلاف کمی در درجه دوم به جریان جوشکاری است. نتایج نشان داد که با هر جنس الکترود به کار رفته در جوشکاری، در صورت افزایش زمان و جریان جوش تا حد متوسط (s4/0 و KA6 ) ، استحکام جوش بهبود پیدا می‌کند. ولی در مقادیر بالای زمان و جریان، تاثیر منفی بر استحکام جوش مشاهده می‌شود. اگرچه جنس الکترود جوشکاری سومین رتبه را در تاثیر بر استحکام جوش دارد، اما راندمان خط تولید در صورت استفاده از الکترودهای تنگستن به مقدار قابل توجه 29.17% نسبت به الکترودهای از جنس مس بیشتر بود. این در حالی است که استحکام جوش توسط الکترود تنگستن فقط به مقدار 5.5% کمتر از الکترود مس است که این استحکام هنوز در محدوده مجاز و قابل قبولی از استانداردهای مربوطه قرار گرفته است. تفاصيل المقالة

فهرس المقالات Resistance spot welding

سند

الروابط

المراكز ذات الصلة

دعامة

الصفحات الرسمية