The Study of Estimating in Ultimate Stress after High Temperature Corrosion

• Main Authors: Chou Shin Chi, 周士琦
• Other Authors: Wang Chaur Jeng
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/33964259917365132304

碩士 === 國立臺灣科技大學 === 機械工程研究所 === 84 === To investigate the accuracy of descaling, the three cleaning methods of ASTM G1 were used. Based on ASTM G54, the low carbon steel was oxidized at 800℃.Compared with the corrosion rates obtained by the OM examination standard reference. The results show that chemical cleaning is better than electrolytic cleaning, while mechanical cleaning produces the worst results. Using OM examination and chemical cleaning to analyze the factors of the area loss ratios among tensile test, the S17CK and the 304 stainless steel were oxidized and NaCl hot corroded in NaCl deposition at 750℃ and 850℃. The results show that the area loss rations of the S17CK steel were not only affected by corrosion, but also by decarburisation , grain growth and phase transformation. On the other hand, the area loss rations of the 304 stainless steel have a good accuracy with OM examination reference. The corrosion morphology of the 304 stainless steel is strong dependent on the testing temperature, being slightly intergranular corrosion at T≦800℃, but being highly internal penetration at T≧800℃. The accuracy of estimating tensile is based on the metal loss method at low temperature, while the total depth of attack method is more accurate at higher temperature.