Fatigue And Friction Properties Of Corrosion-Resistant Magnetically

With the development of the society,there is an increasing demand for the use of materials.Materials are needed to possess of better performance when in practical environment.In practical use,fracture is one of the most important forms for materials to be invalided,which will cause great loss for people.A lot of fracture accidents take place because of material fatigue.Ni-based and Cr-based magnetically soft alloy used on relay was researched. Former research just pays attention to its magnetic ability and corrosion—resistant.It does not study its mechanical property.But fatigue property is very important in its application process because the derail bears cyclic stress.Fatigue properties were studied for three Ni-based and Cr-based at load ratio R=-1.The main conclusions that gained under the above conditions are as follows:1.Adoption of the tension and compression of the material to the determination of fatigue It was found that GYT130σ_-1=228.1 MPa,GYT170σ_-1=193 MPa,and 1J36σ_-1=108.3MPa.Through macro fracture observed that GYT130 and 1J36 have plastic deformation at the scene.GYT170 plastic deformation and fracture is smaller,and brittle is bigger.In the cracks expansion area,GYT130 material has transcrystalline cracking.GYT170 material has intercrystalline cracking and 1J36 material has found obvious fatigue profiling.Friction properties of the material were found that with the increase in frequency,the coefficient of friction is the trend of decreasing,and the volume of wear was increased.2.Adoption of the rotary bending of the material to the determination of fatigue It was found that GYT130σ_-1=228.5MPa,GYT170σ_-1=215 MPa,and 1J36σ-1=127 MPa.Through the materials tension and compression fatigue and rotary bending fatigue results of the comparison,For 1J36,σ_tension=0.85×σ_bending,and for GYT130 and GYT170,their relations wereσ_tension=0.95σ_bendingandσ_tension=0.89×σ_bending.3.Through laser treatment,GYT130 and GYT170 materials were found that theirs grain was refinement,and 1J36 material was found that there was no obvious refinement.After laser treatment,material's micro-hardness was increased significantly, and with the increase of laser energy,the micro-hardness was increased,the depth of hardened layer was deep.Through the study of terminological properties.materials before and after laser treatment was contrast,it was found that after laser materials processing,the wear volume significantly was smaller,and with the increase in processing power,the wear volume was a downward trend.In laser treatment and found that the volatility of the friction coefficient was larger,and after laser treatment in the numerical coefficient of friction was larger.After laser processing,the materials of GYT130 and GYT170's residual was increased with the increase in processing power, and a J36 material wasn't found the result because of its coarse grains,but the stress on the surface was found that with the increased of laser energy,the residual was increased also.