| Stainless steel has corrosion resistance and good mechanical properties,and is widely used in automotive,construction,medical equipment and military fields.The use of traditional subtractive manufacturing methods has the disadvantages of high cost,long manufacturing cycle,and low material utilization.With the development of the manufacturing industry,additive manufacturing uses the stacking principle to combine laser scanning with rapid prototyping to achieve the formation of 316 L stainless steel with a complex structure.At present,research on 316 L stainless steel additive manufacturing sheet metal is very scarce,but sheet metal is an important part of metal forming and occupies most of mechanical manufacturing parts,so 316 L stainless steel additive manufacturing segment has important research value.Because the 316 L stainless steel formed by additive manufacturing technology has residual stress,spheroidization,cracks,pores and other problems,the forming performance is often poor.Based on the forming performance of 316 L stainless steel,this paper the following studies are carried out by analyzing the influence of process parameters on the performance of 316 L stainless steel sheet:By adjusting the technological parameters of additive manufacturing and taking the laser power,scanning speed,and scanning pitch as variables,several groups of316 L stainless steel blocks with different parameters are prepared.According to the forming situation,it is found that small scanner spacing will reduce the success rate of material preparation.The 316 L stainless steel block manufactured by additive manufacturing is cut into unidirectional tensile,shear tensile,plane strain and U-shaped bending specimens by wire cutting,and the static tensile tests are carried out.The relationships between material mechanical properties and manufacturing process are analyzed by processingthe experimental data.It is found that with the increase of the filling laser power,the mechanical properties of the material will rise and then decline,and the performance is best at 300 W.As the scanning speed and scanning distance increase,the mechanical properties of the material will be improved.Through the U-shaped bending test,we found that with the increase of the filling laser power,the spring back of the material shows an increasing trend and then decreases,and it is the largest at 260 W.The spring back will decrease with the increase of the scanning distance,and however,it will increase with the increase of the scanning speed.The performance of 316 L stainless steel is applied to the finite element simulation.Through the simulation of static tensile tests and U-shaped bending tests,the simulation results are extracted and compared with the test results to verify the reliability of the finite element simulation.Based on the finite element analysis software ABAQUS and the fatigue analysis software FE-SAFE,the fatigue life of316 L stainless steel sheet additive manufacturing specimens can be predicted.The Simufact Additive software is used to simulate the forming of uniaxial tensile specimen and steel blocks,and the reason for the failure of printing the 316 L stainless steel block is analyzed from the perspective of simulation.The simulation results successfully explain the phenomenon of low preparation success rate in the experiment,which proved that the simulation can be used for additive manufacturing forming prediction. |
