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991.
992.
针对材质为TP347φ406×60 mm的不锈钢管进行全位置高频窄间隙自动焊接。分析窄间隙坡口尺寸和焊接工艺参数对焊缝成型的影响,试验结果表明,焊接接头的抗拉强度、低温冲击韧性、低温裂纹尖端张开位移值均满足要求。 相似文献
993.
SCS蓄电池箱是机车的重要装备,其焊接主要包括:侧板组焊、隔板组焊、箱体组焊、悬挂焊接、电池斗、电池盒焊接、电池斗装配、箱体组装焊接。详细分析焊接过程中的难点,需按一定的焊接工艺方可保障焊接质量。对同类焊接具有一定的参考价值。 相似文献
994.
995.
设计了基于三菱FX2N型PLC的逆变电阻点焊控制系统。介绍了系统的工作原理,阐述了PLC的PID指令、PWM指令及A/D转换模块在该控制系统中的应用。实际使用表明,该控制系统能够满足使用要求,且控制精度较高。 相似文献
996.
997.
José Gedael Fagundes Junior Rodolfo da Silva Manera Ruís Camargo Tokimatsu Vicente Afonso Ventrella Juno Gallego 《Welding International》2016,30(7):520-526
Equipment of sugar cane plants and mineral extraction are submitted to severe abrasive wear conditions. Welded hardfacings are usually applied to repair this kind of damage, where commercial chromium/carbon-rich welding consumables have usually been employed. In the present work we investigated the microstructure of experimental hardfacings made by addition of residues (chips) collected from the machining of ASTM F67 (unalloyed Ti, grade 4) alloy. Mixtures with different carbide-formers (Cr/Nb ferro-alloys) were also tested. Two layers of ‘pure’ chips (Ti), chips plus Fe–Cr (Ti–Cr), and chips plus Fe–Nb (Ti–Nb) were applied on low-carbon steel specimens by the GTAW/TIG process. The microstructure of hardfacing layers was observed by optical and scanning electron microscopy (SEM) equipped with EDS microanalysis. The microstructural characterization has determined that carbide distributions change significantly with the chemical nature of the hardfacing. SEM observations coupled with EDS microanalysis have confirmed the formation of complex carbides within the metal weld, whose stoichiometry was determined by X-ray diffraction (XRD) analysis. Mixed carbides of MC type and some cementite have been found. As a result it was suggested that use of ASTM F67 chips as carbide formers for composition of welding consumables can contribute to improved wear resistance of hardfacings, if compared with traditional chromium-based hardfacings. 相似文献
998.
Fracture behaviour and numerical study of resistance spot welded joints in high-strength steel sheet
Teruki Sadasue Satoshi Igi Koichi Taniguchi Rinsei Ikeda Kenji Oi 《Welding International》2016,30(8):602-613
Cross tension tests of resistance spot welded joints with varying nugget diameter were carried out using 980 MPa high strength steel sheet of 1.6 mm thickness. In proportion, as nugget diameter increased from 3√t to 5√t (where t is thickness), cross tension strength (CTS) increased while fracture morphology simultaneously transferred from interface fracture to full plug fracture. In cases of interface fracture, circumferential crack initiation due to separation of the corona bond arose at an early stage of loading. The crack opening process without propagation was recognized until just before fracture and then the crack propagated to the nugget immediately in a brittle manner around CTS. In full plug fracture, main ductile crack initiation from the notch-like part at the end of sheet separation occurred with the sub-crack initiated at an early stage. The ductile crack propagated toward the HAZ and base material to form full plug fracture. The mode I stress intensity factor was considered as a suitable fracture parameter because the circumferential crack behaved pre-crack for brittle fracture in the nugget region at the final stage. Based on the FE analysis, the mode I stress intensity factor was calculated as 116 MPa √m at CTS as fracture toughness for the nugget. With respect to full plug fracture, ductile crack initiation behaviour from the notch-like part was expressed by concentration of equivalent plastic strain. On the assumption that the ductile crack arose in critical value of equivalent plastic strain, the value was calculated as 0.34 by FE analysis. Reasonable interpretation for interface fracture and full plug fracture in the resistance spot welded joint was proposed due to first crack initiation by stress concentration, brittle fracture by using mode I stress intensity factor, and ductile crack initiation by using equivalent plastic strain. 相似文献
999.
V.I. Lukin V.G. Kovalchuk N.G. Pokrovskaya E.V. Golev O.A. Bannykh M.V. Antsiferova 《Welding International》2016,30(1):60-64
The optimum filler material was selected and the technological and mechanical properties and structure welded joints are investigated. 相似文献
1000.
Tiago F. A. Santos Edwar A. Torres Tahiana F. C. Hermengildo Antonio J. Ramirez 《Welding International》2016,30(5):338-347
Usually, a workpiece is deformed during friction stir welding due to high applied loads. Consequently, fully and consolidated friction stir-welded joints as well as tool life time can be affected promoting unscheduled manufacturing stops, which favour decreasing the welding productivity. Furthermore, the workforce is dislocated to not predicted maintenance steps. This work proposes the development of a special ceramic backing to joining and processing material using FSW technologies. Four ceramic deposits were tested over a steel plate, which allowed selecting those with less porosity and, thus, better strength. This backing allowed us to obtain full penetration welds for duplex stainless steels, to high forces during engagement for high-strength low-alloy steels and to obtain consolidated aluminium–steel dissimilar joints. For the last one, there was not adherence of the soft material in the workpiece. In addition, the ceramic backing allowed us to confine the heat and plasticized metal, as well as develop established welding parameters. 相似文献