Study Of Mechanical Properties And Corrosion Resistance Of Ferritic Stainless Steel Bearing Cu And Sn

The main components of stainless steel are chromium,nickel and molybdenum.However,nickel and molybdenum are very expensive metals.China is the country of lacking nickel,molybdenum and chromium.Coupled with the supply of nickel resources across the world in the supply of tension,the stainless steel with nickel free stainless steel highlights the huge advantage of low cost.At the same time with the development of industry,the amount of scrap is increasing.Scrap recycling is also a problem.An important problem is scrap recycling process inevitably will lead to the accumulation of copper in steel,which turns steel performance bad.Ferritic stainless steel in many areas has a major purpose with its low linear expansion coefficient and excellent high temperature strength.The strength,thermal fatigue and corrosion resistance of ferritic stainless steels during its use were mainly investigated.This thesis is based on the research of domestic and foreign research status and field technology.With laboratory conditions,add a certain amount of copper in the tin-containing ferritic stainless steel to study the effect of copper content of stainless steel mechanical properties and corrosion resistance.Steel samples were ferritic stainless steel bearing 0.30%tin added 0.13%to 2.54%copper,which smelted by 10 kg vacuum induction furnace and rolled by rolling mill.The result of normal temperature tensile test and high temperature tensile test show that adding 0.45%-2.54%copper in the Sn-containing stainless steel strengthen the tensile strength and yield strength of stainless steel because of the effect of copper atoms in solid solution.It will reduce the plasticity of stainless steel as well.When it contains 0.45%copper,the mechanical properties of materials has little change.When copper content was further increased to 0.98%or higher,plastic material sharply deteriorated.The test results of dynamic potential anode polarization curves showed that adding 0.13%?0.65%copper into ferritic stainless steel bearing tin could increase the pitting potential of stainless steel.When adding 0.36%copper into ferritic stainless steel bearing 0.30%tin,the pitting potential will reach the top.The concentrations of chlorine and temperature have a significant effect on the pitting potential of ferritic stainless steel bearing tin and copper.Uniform immersion test shows that weight loss of ferritic stainless steel is linearly correlated with the time in 40%H2SO4.Corrosion rate is further reduced when adding 0.45%-2.54%copper in the stainless steel bearing 0.30%tin.When the copper content is 0.45%,uniform corrosion resistance of the stainless steel is the lowest,about 0.0672 g·cm-2·h-1.The uniform corrosion resistance is the best.Immersion test shows that adding 0.45%?2.54%copper in the ferritic stainless steel bearing 0.30%tin,the intergranular corrosion resistance of the stainless steel is improved.Adding 0.98%copper in ferritic stainless steel bearing 0.30%tin,the intergranular corrosion resistance is the best.Adding 0.13%?0.93%copper in the Nb and Ti-containing ferritic stainless steel can improve the intergranular corrosion resistance of the stainless steel.