The Research Of Arc Additive Manufacturing Technology Of Marine Stainless Steel

Stainless steel has the characteristics of high cost performance,good corrosion resistance,heat resistance and low temperature resistance.Its application in modern ship and offshore industry,especially chemical tanker,super large LNG ship and seawater desalination device,is becoming more and more extensive.Additive manufacturing technology conforms to the current trend of scientific and technological development,and is in line with the concept of modern green manufacturing,so it is also increasingly valued by modern people.The combination of additive manufacturing technology and shipbuilding is also a hot topic in the field of shipbuilding.Stainless steel additive manufacturing technology has also caused widespread research by scholars at home and abroad.The traditional stainless steel arc additive manufacturing technology is limited to devices such as protective covers that cannot be factoryapplied.In addition,the experimental results of the additive without the protective device are seriously oxidized,which affects the appearance of the additive and increases the trouble of post-additive processing..In this paper,the MIG welding robot is used as a heat source to conduct an in-depth study on the 304 stainless steel arc additive manufacturing technology.First,the welding robot was used to study the effects of different process parameters such as shielding gas,additive current,voltage and additive speed on the deposition of single layer additive.It was found that by appropriately adjusting the additive process parameters,the heat input during the arc additive process can be reasonably controlled.The stainless steel additive test piece with less oxidation and good surface quality was obtained while maintaining excessive dripping in the molten pool.Then based on the good stainless steel arc additive process parameters obtained above,test pieces with different additive layers were fabricated.The characteristics and growth mechanism of the dendrite structure of the additive test piece were studied,and the different grain morphologies in the deposit were explained.The cooling and solidification mechanism of the multilayer deposition process was analyzed.The organization transformation law of the multilayer deposition process is discussed,and then the formation mechanism of the ferrite participating in the additive is studied.The element composition and changes in different regions of the additive test piece were analyzed.Finally,based on the previous experimental research,the numerical simulation calculation of the stainless steel arc additive manufacturing process was carried out.The temperature field of 304 stainless steel 1-6 layer additive manufacturing process was simulated.Some nodes of interest are selected to draw the node thermal cycle curve.It is proved that the combination of body heat rate heat source and birth-death unit method can better simulate the temperature change of the stainless steel arc additive manufacturing process.