Study On All Positions Cutting Process Of 316LN Stainless Steel With PAC

AP1000 nuclear power piping is pressure piping of large thickness, connecting pressure vessels and steam generators, is one of the nuclear level key equipment. Until now, technology of manufacture of AP1000 nuclear power piping is machine processing after integrally forged in China and overseas, difficult and waste of materials. In order to shorten the production cycle and save energy and materials, plasma arc cutting should be used to remove the residual after extrusion molding. Due to the complex structure and big size and weight of the nuclear power piping, it is necessary to adopt all positions plasma arc cutting, namely fixing piping and rotating torch of plasma arc cutting around the piping axis. The angle of removal direction of molten slag and gravity direction is always changing during the all positions plasma arc cutting. So it is impossible to use the same process for the same cutting surface quality. Therefore, it is necessary to do some research of process of all positions plasma arc cutting. Before doing the test of position cutting, it is necessary to get the rules of influence of process parameters on cutting quality. So the influence of process parameters on the cutting quality was studied firstly in this paper, and then the plate was used to simulate the cutting process of all positions.The study of rules of influence of process parameters of plasma arc cutting on cutting quality shows that the influence law curve of four main process parameters on cutting quality varies as concave, that is to say, within the range of process parameters, there is a interval in the middle, which makes the cutting quality better, while poor at the beginning and ending of the range of process parameters. In addition, when increasing the thickness of the plate, the rules of influence on cutting quality are similar but the length of interval will be shortened.simulations of the cutting process of all positions show that the rules of influence on quality are similar but smaller process window compared with the normal cutting, and the cutting current and the cutting speed has great influence on cutting quality while the height of nozzle and the gas pressure are less influence.