C.Y. Choi D.C. Kim D.G. Nam Y.D. Kim Y.D. Park
材料科学技术（英）
Currently, in the automotive industry, joining of the aluminum alloys with the steel is a crucial problem to be solved. Conventional joining techniques including resistance spot and gas metal arc welding are not acceptable for those applications due to a number of metallurgical problems. The investigation was carried out to develop the hybrid joining process combining the resistance spot welding and brazing. In this study, an attempt was made to apply hybrid process to the joining of dissimilar sheet metals, Al-Mg-Si (6000 series) alloy and low carbon steel sheet. Hybrid process (resistance spot weld/brazing) using filler metal was found to be effective to overcome the incompatibility between aluminum alloy and steel. Although hybrid joining process of Al alloy sheet and steel sheet did not produce acceptable bond strength, it was proved to have reasonable interfacial
bond layer if the optimal process condition was applied.
关键词:
Hybrid joining
,
Aluminum
,
Steel
,
Welding
Xudong ZHANG
,
Wuzhu CHEN
,
Gang BAO
,
Lin ZHAO
材料科学技术（英）
This paper describes a way to improve the weld quality through suppressing the porosity formation and restraining the growth of columnar grains by using a weaving beam in laser welding. The experimental results show that the N2 porosity of beam-weaving laser welding low carbon steel can be remarkably reduced with increasing weaving frequency, and porosity can be eliminated when the weaving amplitude is only 0.5 mm; and the Ar porosity in the weld metal is decreased with increasing weaving frequency and amplitude when the welding speed is higher than 0.5 m/min. The beam-weaving laser welding of ultra-fine grained steel has been investigated. The experimental results show that beam-weaving laser welding with appropriate amplitude and frequency can partly restrain the growth of the columnar grain and improve the tensile strength of the weld metal.
关键词:
Welding
,
null
,
null
,
null
C.Y. Choi D.C. Kim D.G. Nam Y.D. Kim Y.D. Park
材料科学技术（英）
Currently, in the automotive industry, joining of the aluminum alloys with the steel is a crucial problem to be solved. Conventional joining techniques including resistance spot and gas metal arc welding are not acceptable for those applications due to a number of metallurgical problems. The investigation was carried out to develop the hybrid joining process combining the resistance spot welding and brazing. In this study, an attempt was made to apply hybrid process to the joining of dissimilar sheet metals, Al-Mg-Si (6000 series) alloy and low carbon steel sheet. Hybrid process (resistance spot weld/brazing) using filler metal was found to be effective to overcome the incompatibility between aluminum alloy and steel. Although hybrid joining process of Al alloy sheet and steel sheet did not produce acceptable bond strength, it was proved to have reasonable interfacial
bond layer if the optimal process condition was applied.
关键词:
Hybrid joining
,
Aluminum
,
Steel
,
Welding
Chuansong WU
,
Jinqiang GAO
材料科学技术（英）
Achieving an effective utilization and exploitation of TIG welding arcs require a thorough understanding of the plasma properties and its physical processes. Through simultaneous solutions of the set of conservation equations for mass, momentum, energy and current, a mathematical model has been developed to predict the velocity, temperature, and current density distributions in argon welding arcs. The predicted temperature fields in arc regions, and the distribution of current density and heat flux at the anode agree well with measurements reported in literatures. This work could lay the foundation for developing a comprehensive model of the TIG welding process where a dynamic, two-way coupling between the welding arc and the weld pool surface is properly represented.
关键词:
Welding
,
null
,
null
,
null
Yajiang LI
,
Bing ZHOU
,
Tao FENG
,
Jiangwei REN
材料科学技术（英）
Microstructure performance in the welding zone of T91 heat-resistant steel under the condition of TIG welding was researched by means of metallography, X-ray diffraction and scanning electron microscope (SEM).Experimental results indicated that microstructure of T91 weld metal was austenite + a little amount of d ferrite when using TGS-9cb filler wire.Substructure inside the austenite grain was crypto-crystal lath martensite, on which some Cr23C6 blocky carbides were distributed. The maximum hardness (HRC44) in the welding zone is near the fusion zone. There existed no obvious softening zone in the heat-affected zone (HAZ). For T91 steel tube of F63 mm×5 mm, when increasing welding heat input (E) from 4.8 kJ/cm to 12.5 kJ/cm, fracture morphology in the fusion zone and the HAZ changed from dimple fracture into quasi-cleavage fracture (QC). Controlling the welding heat input of about 9.8 kJ/cm is suitable in the welding of T91 heat-resistant steel.
关键词:
T91 heat-resistant steel
,
null
,
null
王国庆
,
李曙光
,
吴会强
宇航材料工艺
doi:10.3969/j.issn.1007-2330.2014.Z1.001
大型结构件制造技术是发展重型运载火箭的关键技术之一,直径8～9m级重型运载火箭大型贮箱将带来成型、焊接装配等工艺和装备方面新的制造技术挑战.吸取以往人类历史上研制经验教训,有助于权衡大型结构件制造实现和制造经济性.需开展先进制造技术升级,加强大型轻质化结构制造技术和装备技术基础,适应发展要求.
关键词:
重型运载
,
大型结构制造
,
铝合金
,
成型
,
焊接
