Microstructure and Properties of Plasma Arc Welding Gradient Materials by Additive Manufacturing
The work aims to study the microstructure and mechanical properties of SS 316L stainless steel and Inconel 625 nickel-based alloy gradient material by additive manufacturing under plasma arc welding process.Two kinds of SS 316L stainless steel and Inconel 625 nickel-based alloy arc additive manufacturing samples with and without gradient transition were prepared by non-coaxial wire feeding plasma arc welding.After linear normalization of experimental data,the microstructure and mechanical properties of the two samples at different positions and directions were studied.With the increase of the number of layers,the heat input of each layer at the bottom of the sample with gradient transition decreased layer by layer,which made the bottom additive manufacturing process more stable,while the sample without gradient transition had greater roughness in the connection area of the two metals and uneven formation between layers.The microhardness of the two samples increased with the increase of the layer height,and the microhardness of the samples with gradient transition suddenly decreased from 30％Inconel 625/70％SS 316L to 20％Inconel 625/80％SS 316L,and there was obvious segregation of Mo andNb elements in this region.It was judged that Laves phases were produced.Thin and uniform SS 316L stainless steel and Inconel 625 nickel-based alloy samples by arc additive manufacturing can be obtained by plasma arc welding process.The gradient transi-tion material has more columnar dendrites and less equiaxial dendrites,and the columnar dendrite structure of the crystal region is more uniform,resulting in an increase in microhardness value,and improving the performance of the product.Therefore,the use of transitional gradient materials while avoiding the specific transition zone of 30％Inconel 625/70％SS 316L to 20％In-conel 625/80％SS 316L can effectively improve the product performance of this process.
万方数据
维普
