Corrosion Science and Technology

The Corrosion Science Society of Korea (한국부식방식학회)
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Effects of Induction Heat Bending Process on Microstructure and Corrosion Properties of ASME SA312 Gr.TP304 Stainless Steel Pipes

  • Kim, Nam In (Materials Research Center for Clean and Energy Technology, School of Materials Science and Engineering Materials, Andong National University) ;
  • Kim, Young Sik (Materials Research Center for Clean and Energy Technology, School of Materials Science and Engineering Materials, Andong National University) ;
  • Kim, Kyung Soo (KEPCO Engineering & Construction Company, Power Engineering Research Institute) ;
  • Chang, Hyun Young (KEPCO Engineering & Construction Company, Power Engineering Research Institute) ;
  • Park, Heung Bae (KEPCO Engineering & Construction Company, Power Engineering Research Institute) ;
  • Sung, Gi Ho (R&D Center, Sungil SIM)
  • Received : 2015.01.08
  • Accepted : 2015.06.29
  • Published : 2015.06.30
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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.

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References

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Cited by

  1. Applicability of the induction bending process to the P91 pipe of the PGSFR vol.53, pp.5, 2021, https://doi.org/10.1016/j.net.2020.10.021