Research On The Properties Of CP800 Laser Welding By The Following Arc

In this paper, we use CO2 laser and DC TIG arc to study on the property improving of laser welding seam, in order to gain a real-time weld heat treatment process. First of all, for the automotive steel CP800 Multi-phase steel thickness and material properties, we set the corresponding parameters of laser welding process. Then, according to the actual situation we set the TIG arc current and the spacing between the laser and arc, and make a temperature simulation in the finite element analysis software-ANSYS. After that, we design different arc current values and different arc - laser distance, and make the microstructure analysis, test the mechanical properties. Based on the testing and analysis results, we research on he welded joint performance of different current values and different arc - Laser space.Current values have different impacts on the structures and properties of the weld seam. With the current size increases, the heat affected zone broadens. Under the same current size, as the distance between laser and arc increases, the effect on the upper and lower surface of the heat-affected zone decreases.Under the same laser-arc space, with the arc current increases, the upper surface hardness of weld fusion zone gradually reduces, the hardness of 25A is 408.5HV, the hardness of 75A is 401.8HV, and the hardness of heat-affected zone increases, but not obvious. Similarly, under the same arc current, with the increasing in laser-arc space, the weld hardness reduces, the hardness of 17mm is 401.8HV, the hardness of 32mm is 411.3HV. In addition, if using the small current circumstances, as the distance enlarges, the arc is more unstable. While the laser-arc distance is close, we obtain the same results. For the lower surface, the impact is negligible and can not be considered. The weld toughness is higher than the base metal.Under short distance, the arc is relatively stable. With the increase in laser-arc distance, the arc flowing becomes more obvious and more unstable. When the distance is beyond 32mm, the arc begins to stabilize (becoming two unaffected heat sources). With the arc increases, the distance becomes longer for stabilizing the arc. By the effects of welding speed, the arc shows a certain degree of discontinuity. Welding speed increases, the more obvious discontinuity emerges. It would enable a continuous electric arc heating methods by reducing the welding speed.In simulation, through the nebula map we obtain weld shape map, and the results are basically consistent with the measured values. Arc has no effect on thermal cycling in regions the arc hasn't passed. For the same kinds of power of the arc, a little farther distance will get better results of welding thermal cycle. Under the same kinds of distance, with the power increases, the impact on the welding thermal cycle becomes greater.