The Effect of Silicon Content on the High Temperature Oxidation

• Main Authors: Lin, Shyh-An, 林世安
• Other Authors: Wen-Ta Tsai, Ju-Tung Lee
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/31202898286838666273

碩士 === 國立成功大學 === 材料科學(工程)學系 === 84 === The purpose of this study was to investigate the high temperature oxidationbehavior of AISI 310 SS and silicon- containing stainless steels produced by Laser Surface Cladding (LSC) process. The effects of silicon on the oxidationbehavior of stainless steels were also explored. Thermogravimetric analyses(TGA)were conducted between 700~1000℃ in 0.5 atm oxygen partial pressure. SurfaceSurface morphology of the oxides formed on the alloy surface after different exposure time, ranging from 1 to 144 hour, in 1 atm air between 700~1000℃ wasexamined. The structure and chemical composition of the oxides formed after theoxidation test were also analyzed. TGA results showed that oxidation kinetics of all alloys studied follow the parabolic rate law. The oxidation rates of the alloys studied increase in the following order: LSC-B(1.84wt% Si), LSC-C(3.32wt% Si), AISI 310 SS, LSC-A(without Si). The results indicated that the addition of Si to stainless steelscould improve its oxidation resistance, but there was an ultimate content of Sion improving the oxidation resistance of the LSC alloys. In excess of the ultimate value, the beneficial effect of Si on improving the oxidation resistance disappeared. The oxides formed on AISI 310 SS in 1 atm air between700~1000℃ were (Mn,Cr,Fe)3O4/Cr2O3/SiO2. The oxide formed of LSC-A alloy wasCr2O3 at 700~900℃. At 1000℃, the oxide formed constituted with a Cr2O3 innerlayer and an outer layer of (Fe,Cr)2O3 with some Ni-rich oxide disperseddiscontinuously in it. For LSC-B alloy, the oxide formed in 1 atm air at 700~900℃ was Cr2O3, and the oxides were Cr2O3/SiO2 at 1000℃. For LSC-C alloy, only Cr2O3 was identified in the same environment.