Research On Mechanical Properties Of Welding Joint Made By Pulsed Submerged Arc Welding Technology And Application In Engineering

Now Submerged Arc Welding (SAW) has been used as one of the welding technologies of high mechanization widelyTo solve the disadvantages of normal SAW such as grain coarsening, increase in the brittleness, decrease in the tenacity and increase in the sensitivity of flaw when Submerged Arc Weld (SAW) is applied with high heat input, this paper put forward a new pulsed current SAW technology.This paper presented the brief principle of MCU-cored pulse controller. Numbers of experiments were designed and finished with the help of orthogonal means.This paper chooses the armor plate of 16MnR(δ=12mm) as the test material, studies the effects of pulse parameters(background current, peak pulse current, frequency and duty cycle )on the welds shaping and mechanical properties. The results of the experiments shows that mechanical properties can be obviously increased by pulsed SAW, especially impact tenacity of welding joint when using sharp-fall output characteristics power source and varying-speed wire feeder comparing with the ordinary SAW when using equal heat input. This paper has analyzed the mechanism of improving mechanical properties of welding joint welding by pulsed SAW: Such regular change of pulsed current helps molten pool's surging and churning and it can obtain lesser grain size, reduce concentration change of molten pool metal, decrease the composition segregation of deposited metal, and enhance mechanical properties of deposited metal.In conclusion, the technology of pulsed SAW that put forward in this paper is an easy and efficient method of welding technology, and the developed pulse controller is easy to manipulate and dependable to run.The research has widely prospect in application in the weld of low temperature steel and the important welded construction(example low temperature pressure vessel ,shipping ) with be required to ensure mechanical properties especially low temperature impact tenacity of welding joint, and it has important merit in practical engineering.