Intergranular corrosion(IGC) behavior of the stabilized ultra-pure 430 LX ferritic stainless steel(FSS) was investigated by using double loop electrochemical potentiokinetic reactivation(DL-EPR) and oxalic acid etch t...Intergranular corrosion(IGC) behavior of the stabilized ultra-pure 430 LX ferritic stainless steel(FSS) was investigated by using double loop electrochemical potentiokinetic reactivation(DL-EPR) and oxalic acid etch tests to measure the susceptibility of specimens given a two-step heat treatment. The results reveal that IGC occurs in the specimens aged at the temperature range of 600–750℃ for a short time. The aging time that is required to cause IGC decreases with the increase of aging temperature. A longer aging treatment can reduce the susceptibility to IGC. The microstructural observation shows that M(23)C6 precipitates form along the grain boundaries, leading to the formation of Cr-depleted zones. The presence of Cr-depleted zones results in the susceptibility to IGC. However, the atoms of stabilizing elements replace chromium atoms to form MC precipitates after long-time aging treatment, resulting in the chromium replenishment of Cr-depleted zones and the reduction of the susceptibility to IGC.展开更多
The microstructure evolution and intergranular corrosion(IGC) behavior of high nitrogen martensitic stainless steels(MSSs) by partial replacing C by N were investigated by using microscopy, X-ray diffraction, nitric a...The microstructure evolution and intergranular corrosion(IGC) behavior of high nitrogen martensitic stainless steels(MSSs) by partial replacing C by N were investigated by using microscopy, X-ray diffraction, nitric acid tests and double-loop electrochemical potentiokinetic reactivation(DL-EPR) tests. The results show that the partial replacement of C by N first reduces and then increases the size and content of precipitates in high nitrogen MSSs, and converts the dominant precipitates from M23C6 to M2N,furthermore first improves and then deteriorates the IGC resistance. The high nitrogen MSS containing medium C and N contents provides good combination of mechanical properties and IGC resistance.展开更多
基金financial support from the National Key Research and Development Program of China (No. 2018YFB0704400)the National Natural Science Foundation of China (Nos. 51501041, 51871061 and 51671059)
文摘Intergranular corrosion(IGC) behavior of the stabilized ultra-pure 430 LX ferritic stainless steel(FSS) was investigated by using double loop electrochemical potentiokinetic reactivation(DL-EPR) and oxalic acid etch tests to measure the susceptibility of specimens given a two-step heat treatment. The results reveal that IGC occurs in the specimens aged at the temperature range of 600–750℃ for a short time. The aging time that is required to cause IGC decreases with the increase of aging temperature. A longer aging treatment can reduce the susceptibility to IGC. The microstructural observation shows that M(23)C6 precipitates form along the grain boundaries, leading to the formation of Cr-depleted zones. The presence of Cr-depleted zones results in the susceptibility to IGC. However, the atoms of stabilizing elements replace chromium atoms to form MC precipitates after long-time aging treatment, resulting in the chromium replenishment of Cr-depleted zones and the reduction of the susceptibility to IGC.
基金supported by the National Natural Science Foundation of China [grant numbers 51434004, U1435205, 51774074]Fundamental Research Funds for the Central Universities [N172512033, N172507002]Transformation Project of Major Scientific and Technological Achievements in Shenyang [grant number Z17-5-003]
文摘The microstructure evolution and intergranular corrosion(IGC) behavior of high nitrogen martensitic stainless steels(MSSs) by partial replacing C by N were investigated by using microscopy, X-ray diffraction, nitric acid tests and double-loop electrochemical potentiokinetic reactivation(DL-EPR) tests. The results show that the partial replacement of C by N first reduces and then increases the size and content of precipitates in high nitrogen MSSs, and converts the dominant precipitates from M23C6 to M2N,furthermore first improves and then deteriorates the IGC resistance. The high nitrogen MSS containing medium C and N contents provides good combination of mechanical properties and IGC resistance.
