Research And Modle Of The GMAW-P Welding Pulse Parameters To The Droplet Transion And The Bead Shape

The Gas Melt Arc Welding-Pulse (GMAW-P) , suit for the entirely location welding , can be well controllable in the welding process, the bead forms shapely ,and be widely used in the actual manufacture. GMAW-P had lots of process parameters, is hard to control effectively. The parameters include :Arc voltage, the welding rate and the Pulse Parameter (Pulse Current , Pulse Time, Background Current ,Background Time, etc). The droplet transition format include : Multi Pulse One droplet, One Pulse One droplet and One Pulse Multi droplet. The Bead shape and dimension had great infection to the welding quality, to make sure the stability of welding process and get a better welding technics performance. Through the research we could get a experiential formula to get a best Welding Droplet transition format, and get a model between the Pulse Parameters and Bead shape Parameter for make sure a best Bead shape and dimension.The paper rely on the Labview signal collection tool to get the Pulse Parameters, use the high speed photography to get the Droplet transition photos information and use the digital GMAW-P welding Power fabricate by self to setup the Pulse Parameters. The paper made the research of the infection by the Pulse Parameters to Droplet transition formats , establish the experience formula to select the pulse parameters to control the One pulse on droplet transition format. And the paper made the research of the infection by the Pulse Parameters to the Welding Bead Shape, establish the model based on the least squares method regression analysis , and to find the relationship between Pulse Parameters and Bead shape dimensions.First , the research develop the GMAW-P digital welding power based on the DSP and MCU, the human-machine interface using the TMS320F240(DSP) and the AT89C52(MCU) as the core, and with this human-machine interface we could set up the pulse parameters accurately and can show the parameters synchronously. The Research establish the experience formula to select the pulse parameters to control the One pulse on droplet transition format: Ip²Tp=434.45(A²*S)That shows the Ip and Tp are the inverse ratio when the transition format is One pulse one droplet, and the Average current isn't the effective factor to the One pulse one droplet transition.Then the research establish the model based on the least squares method regression analysis to find the relationship between Pulse Parameters and Bead shape dimensions: Z_Hi= 0 .2676X_i² +1.53X_i-0.838Y_i²+4.111Y_i-0.2983X_iY_i-4.34 Z_Bi= -13.37X_i² +40.817X_i+1.078Y_i²-3.96Y_i-0.39X_iY_i-16.3 Z_ai = 1. 0718X_i² -1.668X_i-0.1367Y_i²+0.2189Y_i+0.2995X_iY_i+2.407This model can reach the 95.17% veracity to forecast the Bead Shape. That shows the Penetration is deepest when the One pulse one droplet transition, and the Bead width is the most narrow when the One pulse one droplet transition, and the Bead height had no large influence under the three kinds of the droplet transition.