Stainless steels such as STS 304,316 and 630 are frequently used as shaft materials in small fiber reinforced polymer(FRP) fishing boats.If the shaft material is exposed to a severely corrosive environment such as sea...Stainless steels such as STS 304,316 and 630 are frequently used as shaft materials in small fiber reinforced polymer(FRP) fishing boats.If the shaft material is exposed to a severely corrosive environment such as seawater,it should be protected using appropriate methods.The impressed current cathodic protection was used to inhibit corrosion in shaft materials.In anodic polarization,passivity was remarkably more evident in STS 316 stainless steel than in STS 304 and STS 630.The pitting potentials of STS 304,316,and 630 stainless steels were 0.30,0.323,and 0.260 V,respectively.The concentration polarization due to oxygen reduction and activation polarization due to hydrogen generation were evident in the cathodic polarization trends of all three stainless steeds.STS 316 had the lowest current densities in all potential ranges,and STS 630 had the highest.Tafel analysis showed that STS 316 was the most noble in the three.In addition,the corrosion current density was the lowest for STS 316.展开更多
This paper is devoted to the study of frequency effects on hardness profile of AISI 4340 spline shaft heat-treated by induction through an extensive 3D finite element method simulation and structured experimental inve...This paper is devoted to the study of frequency effects on hardness profile of AISI 4340 spline shaft heat-treated by induction through an extensive 3D finite element method simulation and structured experimental investigation. Based on coupled electromagnetic and thermal fields analysis, the 3D model is used to estimate the temperature distribution and the hardness profile. The proposed study examines the hardening process parameters, such as frequency, induced current density and heating time, known to have an influence on hardened surface and builds the simulation model step by step. The established model can provide not only an accurate prediction of temperature distribution and hardness profile but also a comprehensive analysis of machine parameters effects, especially the frequency. The numerical results achieved by this model are good and present a great agreement to the experimental data.展开更多
文摘Stainless steels such as STS 304,316 and 630 are frequently used as shaft materials in small fiber reinforced polymer(FRP) fishing boats.If the shaft material is exposed to a severely corrosive environment such as seawater,it should be protected using appropriate methods.The impressed current cathodic protection was used to inhibit corrosion in shaft materials.In anodic polarization,passivity was remarkably more evident in STS 316 stainless steel than in STS 304 and STS 630.The pitting potentials of STS 304,316,and 630 stainless steels were 0.30,0.323,and 0.260 V,respectively.The concentration polarization due to oxygen reduction and activation polarization due to hydrogen generation were evident in the cathodic polarization trends of all three stainless steeds.STS 316 had the lowest current densities in all potential ranges,and STS 630 had the highest.Tafel analysis showed that STS 316 was the most noble in the three.In addition,the corrosion current density was the lowest for STS 316.
文摘This paper is devoted to the study of frequency effects on hardness profile of AISI 4340 spline shaft heat-treated by induction through an extensive 3D finite element method simulation and structured experimental investigation. Based on coupled electromagnetic and thermal fields analysis, the 3D model is used to estimate the temperature distribution and the hardness profile. The proposed study examines the hardening process parameters, such as frequency, induced current density and heating time, known to have an influence on hardened surface and builds the simulation model step by step. The established model can provide not only an accurate prediction of temperature distribution and hardness profile but also a comprehensive analysis of machine parameters effects, especially the frequency. The numerical results achieved by this model are good and present a great agreement to the experimental data.
