Journal of Welding and Joining

The Korean Welding and Joining Society (대한용접접합학회)
권호 표지
DOI QR코드

DOI QR Code

A Study of Characteristics on the Dissimilar Metals (Alloy Steel : A387 Gr. 91 - Carbon Steel : A516 Gr. 70) Welds Made with FCA Multiple Layer Welding : Part 1

합금강(ASTM A387 Gr. 91) - 탄소강(ASTM A516 Gr.70) 이종금속의 FCA 다층 용접부 특성 평가 : Part. 1

  • 신태우 (한국기술교육대학교 신소재공학과) ;
  • 장복수 (정우산기(주)) ;
  • 고진현 (한국기술교육대학교 신소재공학과)
  • Received : 2016.03.04
  • Accepted : 2016.05.16
  • Published : 2016.06.30
Download PDF
⟨ Previous Next ⟩

Abstract

Characteristics of dissimilar metal welds between alloy steel ASTM A387 Gr. 91 and carbon steel ASTM A516 Gr.70 made with Flux cored arc welding(FCAW) have been evaluated in terms of microstructure, mechanical strength, chemical analysis by EDS as well as corrosion test. Three heat inputs of 15.0, 22.5, 30.0kJ/cm were employed to make joints of dissimilar metals with E91T1-B9C wire. Post-weld heat treatment was carried out at $750^{\circ}C$ for 2.5 h. Based on microstructural examination, tempered martensite and lower bainite were formed in first layer of weld metal. The amount of tempered martensite was decreased and the amount of lower bainite was increased with increasing heat input and layer. Heat affected zone of alloy steel showed the highest hardness due to the formation of tempered Martensite and lower Bainite. Tensile strengths of dissimilar welds decreased with increasing heat inputs. Dissimilar welds seemed to have a good hot cracking resistance due to the low HCS index below 4. The salt spray test of dissimilar metals showed that the corrosion rate increased with increasing heat inputs due to the increase of the amount of lower Bainite.

Keywords

References

  1. Il-Wook Han, Soon-Taik Hong, Development trend of steel and welding consumables for pressure vessel, Journal of KWJS, 28(2) (2010), 125-132 (in Korean)
  2. Gwang-soo Kim, Gi-sik Rho, Considerations in welding for the Cr-Mo type steel pressure vessels, Journal of KWJS, 18(1) (2000), 30-37 (in Korean)
  3. Eung-Joon Kim, Welding fabrication technology of pressure vessels, Journal of KWJS, 18(1) (2000), 38-45 (in Korean)
  4. Hyun-Byung Chae, Manufacturing welding technology of pressure vessels for industrial applications, Journal of KWJS, 28(2) (2010), 133-141 (in Korean)
  5. Ho-Chun Yoo, Effect of Cr, Nb and Ti on the properties in HAZ of A516-70 steels with low HIC-susceptibility, Proceedings of KWS, (1998), 138-139 (in Korean)
  6. Won-Chan Seo, Kook-Soo Bang and Byung-Ha Chi, Effects of carbon content on the weldability of B-containing $620^{\circ}C$ grade high Cr ferritic cast steel for turbine casing, Journal of KSOE, 22(6) (2008), 41-45 (in Korean)
  7. Krauss G, Principles of heat treatment of steels, Metals Park(OH): American society of metals(ASM), (1980)
  8. Willby C, Walters J, Material choice for the commercial fast reactor steam generators In:Pugh SF, Little EA, editors. Proceedings of the international conference on ferritic steels for fast reactor steam generators, London: British nuclear energy society(BNES), (1978), 9-40
  9. Sanderson SJ, Mechanical properties and metallurgy of 9Cr-1Mo steel, In:Khare AK, editor. Proceedings of the international conference on production, Fabrication and properties and application of ferritic steels for high temperature applications. Metals Park(OH): ASM, (1982), 9-85
  10. Wood DS, Materials property requirements for steam generator components in the creep range, Nucl technol, 55(1981), 8-332
  11. Ghang-Soo Kim, Dae-Soon Kim, A study on the charpy impact property of the FCAW welds for low temperature service, Proceedings of KWS, 39 (2002), 85 (in Korean)
  12. Young-Tae Yoo, Ho-Jun Shin, Dong-Gyu Ahn, Kie-Gon Im, Dissimilar metal welding of austenite stainless steel and low carbon steel using CW Nd:YAG Laser, Journal of KSPE, 22(8) (2005), 17-26 (in Korean)
  13. In-June Moon, Bok-Su Jang, Se-Cheol Kim, Jin Hyun Koh, A study characteristics of dissimilar welds between super duplex stainless steel INS S32750 and Carbon steel A516-70 with FCAW, Journal of KWJS, 32(4) (2014), 26-33 (in Korean)
  14. KWJS, II ferrous & non-ferrous metals, Manual of welding and joining, (2008), 289 (in Korean)
  15. H.K.D.H. Bhadeshia, Martensite and Bainite in Steels: Transformation Mechanism & Mechanical Properties, Supplement au Journal de Physique, (3) (1997), 367-376