Effects of Induction Heat Bending Process on Microstructure and Corrosion Properties of ASME SA312 Gr.TP304 Stainless Steel Pipes
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The usage of bending products recently have increased since many industries such as automobile, aerospace, shipbuilding, and chemical plants need the application of pipings. Bending process is one of the inevitable steps to fabricate the facilities. Induction heat bending is composed of compressive bending process by local heating and cooling. This work focused on the effect of induction heat bending process on the properties of ASME SA312 Gr. TP304 stainless steel pipes. Tests were performed for base metal and bended area including extrados, intrados, crown up, and down parts. Microstructure was analyzed using an optical microscope and SEM. In order to determine intergranular corrosion resistance, Double Loop Electrochemical Potentiokinetic Reactivation (DL-EPR) test and ASTM A262 practice A and C tests were done. Every specimen revealed non-metallic inclusion free under the criteria of 1.5i of the standard and the induction heat bending process did not affect the non-metallic inclusion in the alloys. Also, all the bended specimens had finer grain size than ASTM grain size number 5 corresponding to the grain sizes of the base metal and thus the grain size of the pipe bended by induction heat bending process is acceptable. Hardness of transition start, bend, and transition end areas of ASME SA312 TP304 stainless steel was a little higher than that of base metal. Intergranular corrosion behavior was determined by ASTM A262 practice A and C and DL-EPR test, and respectively step structure, corrosion rate under 0.3 mm/y, and Degree of Sensitization (DOS) of 0.001 ~ 0.075 % were obtained. That is, the induction heat bending process didn’t affect the intergranular corrosion behavior of ASME SA312 TP304 stainless steel.
Abstract
The usage of bending products recently have increased since many industries such as automobile, aerospace, shipbuilding, and chemical plants need the application of pipings. Bending process is one of the inevitable steps to fabricate the facilities. Induction heat bending is composed of compressive bending process by local heating and cooling. This work focused on the effect of induction heat bending process on the properties of ASME SA312 Gr. TP304 stainless steel pipes. Tests were performed for base metal and bended area including extrados, intrados, crown up, and down parts. Microstructure was analyzed using an optical microscope and SEM. In order to determine intergranular corrosion resistance, Double Loop Electrochemical Potentiokinetic Reactivation (DL-EPR) test and ASTM A262 practice A and C tests were done. Every specimen revealed non-metallic inclusion free under the criteria of 1.5i of the standard and the induction heat bending process did not affect the non-metallic inclusion in the alloys. Also, all the bended specimens had finer grain size than ASTM grain size number 5 corresponding to the grain sizes of the base metal and thus the grain size of the pipe bended by induction heat bending process is acceptable. Hardness of transition start, bend, and transition end areas of ASME SA312 TP304 stainless steel was a little higher than that of base metal. Intergranular corrosion behavior was determined by ASTM A262 practice A and C and DL-EPR test, and respectively step structure, corrosion rate under 0.3 mm/y, and Degree of Sensitization (DOS) of 0.001 ~ 0.075 % were obtained. That is, the induction heat bending process didn’t affect the intergranular corrosion behavior of ASME SA312 TP304 stainless steel.
참고문헌 (10)
- "ASME Ⅱ, Part A Ferrous Materials Specifications (Beginning to SA-450)", ~ (2011)
- "ASTM A262, Standard practices for detecting susceptibility to intergranular attack in austenitic stainless steels", ~ (2002)
- H. Blume, , Energy Dev, 12, pp.9~ (1983)
- W. D. Callister, Jr, "Materials Science and Engineering" (2003), An Introduction, John Wiley & Sons, Inc
- 신민철, "원자력발전소용 316 스테인리스강 배관의 부식특성에 미치는 유도가열벤딩공정의 영향", CORROSION SCIENCE AND TECHNOLOGY, 13(3), pp.87~94 (2014), 한국부식방식학회[DOI]
- H. C. Choe, , J. Corros. Sci. Soc. of Kor, 21, pp.239~ (1992)
- Y. H. Kim, , J. Corros. Sci. Soc. of Kor, 21, pp.111~ (1992)
- "ASTM G108, Standard test method for electrochemical reactivation (EPR) for detecting sensitization of AISI type 30 and 304L stainless steels", ~ (1994)
- "ISO 4697, Steel-Determination of content of non-metallic inclusions micrographic method using standard diagrams", ~ (2013)
- "ASTM E112, Standard test method for determining average grain size", ~ (2004)