Study On The Thermoplasticity And Mechanical Properties Of Copper-containing Low Nickel Austenitic Stalnless Steel

With the increasing demand for stainless steel, resource consumption of nickel is also increasing. In order to reduce the cost of stainless steel, we need to develop a low nickel stainless steel. In this paper, by testing the mechanical properties of copper-containing low nickel austenitic stainless steel, we studied it's thermoplastic and mechanical properties, and through the experiment The main conclusions are drawn as follows:(1) With increasing temperature, the hot ductility (or pyroplasticity) of two samples was improved firstly, which accompanied by a big ratio of section. But when the temperature rised more, their plasticity decreased as well as the ratio of section.(2) Between 1150℃and 1250℃, the samples TDL-1 and TDL-2 both possessed good thermoplasticity, from which we can figure out that this temperature range will be a suitable heating process temperature range for the two samples. Their tensile strength went down as the stretching temperature increased. Besides, at the same stretching temperature, their tensile strength was not so far different.(3) While the heating temperature went down, crystal particles in the structure showed dynamic recovery, dynamic recrystallization and growth. In addition, when the temperature was near 1200℃, the crystal particles was the finest.(4) The thermoplasticity of the stainless steel was much impacted by the shape of ferrite in the organization. When its shape was nutty structure, the sample occupied good thermoplasticity, however, when it was distributed in the shape of net in the structure, its thermoplasticity decreased.(5) With the increasing of Cu content, the thermoplasticity of the stainless steel went up, which demonstrated that the introduction of Cu in the steel can notably impact.(6) The thermoplasticity of stainless steel including Cu descended, owing to that the interaction of Cu, S in the alloy and O in the air generated some brittle compounds like Cu2S and Cu2O.(7) By observation of organization, austenitic shape change induce martensitic phase transition phenomenon can be both observed in the two samples, and a bigger distortion led to more martensite.