Transactions of the China Welding Institution 

About: Transactions of the China Welding Institution is an academic journal. The journal publishes majorly in the area(s): Welding & Heat-affected zone. Over the lifetime, 1197 publications have been published receiving 2355 citations.

A new heat source model in numerical simulation of high energy beam welding

Abstract: The typical molten pool of high energy beam welding is in nailhead shape with large aspect ratio. In order to simulate it more precisely, a new heat source model, Rotary-Gauss body heat source model, is established. Numerical simulation and experiment are performed to verify it. The results indicate that using the new model can obtain a better result in temperature field computation compared with other heat source models. In addition, the comparison and analysis are helpful to understand the characteristics of different heat source models deeply, so that it will be easier to choose the right heat source model to simulate the high energy beam welding with high efficiency.

Modeling of welding pool surface reflectance of aluminum alloy pulse GTAW

Abstract: The key to the surface height calculation of pulse GTAW welding pool based on shape from shading (SFS) is to build up a surface model of welding pool. Based on the imaging characteristics of aluminum alloy pulse GTAW welding pool, the surface reflectance model is built after analyzing arc intensity, filter system, welding pool shape and reflectance characteristics. With smooth constraint condition of the welding pool surface and variable factor successive over relaxation(SOR) method, the height of welding pool surface is calculated and the error is analyzed.

Electric arc shape of twin-wire indirect arc welding

Abstract: With high speed camcorder system and digital oscillogragh,the electic arc shape of twin-wire indirect arc welding was investigated.Results show that the arc was burning between the two wires in twin-wire indirect arc welding,and the arc was still a type of gas discharge in nature.Welding current,arc voltage and the distance between the two wires and the workpiece have great influence on the arc shape.With the welding current changing,the arc shape presents different degree of concentration and scatter.The arc becomes brighter and bigger with the increase of arc volgage.When the distance between the two wires and the workpiece reduced,the arc concentrated and became shorter and brighter.Arc voltage changes periodically,and its corresponding electric arc shape changes also periodically,and it has well corresponding relationship between arc voltage and electric arc shape.

Some Discussions on Principle of Causing and Relieving Welding Residual Stress

Abstract: In order to explain some different views about principle of causing and relieving welding residual stress, a steel bar with two constrained ends and a long welded plate are analyzed as one-dimensional models. Two thennal cycles are used. One includes heating and cooling stages and the other includes only cooling stage directly from high temperature to room temperature. The results show that in the -welds the residual compressive plastic strains are caused in the former case and the residual contractive thermal strains are caused in the second case. Their actions are equivalent for causing the welding residual stress. However it is the best way to introduce the concept of inherent strain which includes the thermal strain ,plastic strain and phase transformation strain caused in welding cycle and can be considered as a source of welding stress. Some relative problems are dbcussed in this paper.

TIG welding of the stainless steel 304 based on the ultrasonic vibration

Abstract: Stainless steel 304 is one sort of the austenitic stainless steel for most extensive use.It has excellent corrosion resisting and fire resisting property,high hypothermic strength and fine mechanical property.Its welding method is TIG in common use.The TIG welding method is an inefficient welding method because of its shallow penetration and low welding speed,the grain size of the weld is also inclined to grow up which may reduce the performance of the weld.Ultrasonic treatment is an effective way to minimize the grain size and improve the microstructure in the process of metal freezing.Ultrasonic treatment was lead in the process of TIG welding of stainless steel 304 to increase the welding efficiency and improve the weld property.Build-up welding experiments were taken on the flat plate.The results showed that the weld penetration and depth-to-width ratio increase and the crystallizing mode change from columnar crystals to small dentrite equiaxed crystals.Also,the grain size reduce and the organization of the fusion area is uniformed.