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Effect of Restraint Stress on the Precipitation Behavior and Thermal Fatigue Properties of Simulated Weld Heat Affected Zone in Ferritic Stainless Steel
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  • Journal title : Journal of Welding and Joining
  • Volume 33, Issue 6,  2015, pp.6-12
  • Publisher : The Korean Welding and Joining Society
  • DOI : 10.5781/JWJ.2015.33.6.6
 Title & Authors
Effect of Restraint Stress on the Precipitation Behavior and Thermal Fatigue Properties of Simulated Weld Heat Affected Zone in Ferritic Stainless Steel
Han, Kyutae; Kang, Yongjoon; Lee, Sangchul; Hong, Seunggab; Jeong, Hongchul; Lee, Changhee;
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Thermal fatigue life of the automobile exhaust manifold is directly affected by the restraint force according to the structure of exhaust system and bead shape of the welded joints. In the present study, the microstructural changes and precipitation behavior during thermal fatigue cycle of the 18wt% Cr ferritic stainless steel weld heat affected zone (HAZ) considering restraint stress were investigated. The simulation of weld HAZ and thermal fatigue test were carried out using a metal thermal cycle simulator under complete constraint force in the static jig. The change of the restraint stress on the weld HAZ was simulated by changing the shape of notch in the specimen considering the stress concentration factor. Thermal fatigue properties of the weld HAZ were deteriorated during cyclic heating and cooling in the temperature range of to due to the decrease of Nb content in solid solution and coarsening of MX type precipitates, laves phase, with coarsening of grain and softening of the matrix. As the restraint stress on the specimen increased, the thermal fatigue life was decreased by dynamic precipitation and rapid coarsening of the precipitates.
Thermal fatigue;Ferritic stainless steel;Heat affected zone;Precipitation;
 Cited by
N. Matsuura, The 2nd Annual Conference of the International Stainless Steel Forum, Market Development Committee (1998), 1-16

N. Fujita, H.K.D.H. Bhadeshia, M. Kikuchi, Modelling $M_6C$ precipitation in Niobium-alloyed ferritic stainless steel, Metall. Mater. Trans. A. 33 (2002), 3339-3347 crossref(new window)

N. Fujita, M. Kikuchi, K. Ohmura, Expressions for solubility products of $Fe_3Nb_3C$ carbide and $Fe_2Nb$ Laves phase in Niobium alloyed ferritic stainless steels, ISIJ Int. 43 (2003), 1999-2006 crossref(new window)

N. Fujita, K. Ohmura, A. Yamamoto, Changes of microstructures and high temperature properties during high temperature service of Niobium added ferritic stainless steels, Mater. Sci. Eng. A. 351 (2003), 272-281 crossref(new window)

S.S. Manson, Metal Fatigue Damage-Mechanism, Detection, Avoidance, and Repair, ASTM Special Technical Publication, (1971), 61-122

S.H. Kim, S.C. Lee, K. Han, S. Hong, C. Lee, Cracking behavior in a dissimilar weld between high silicon nodular cast iron and ferritic stainless steel, Met. Mater. Int. 16 (2010), 483-488 crossref(new window)

J.K. Kim, S. Hong, K.B. Kang, C.Y. Kang, Microstructure and high temperature properties of the dissimilar weld between ferritic stainless steel and carbon steel, Met. Mater. Int. 15 (2009), 843-849 crossref(new window)

K. Han, S. Hong, C. Lee, The effect of the precipitates type on the thermal fatigue properties of 18% Cr ferritic stainless steel weld HAZ, Mater. Sci. Eng. A 546 (2012), 97-102 crossref(new window)

D. Oh, K. Han, S. Hong, C. Lee, Effects of alloying elements on the thermal fatigue properties of the 15wt% Cr ferritic stainless steel weld HAZ, Mater. Sci. Eng. A 555 (2012), 44-51 crossref(new window)

D. Radaj, C.M. Sonsino, Fatigue assessment of welded joints by local approaches, Abington Publishing, Cambridge (1998)

F.V. Lawrence, R.J. Mattos, Y. Higashida, J.D. Burk, Estimating the fatigue crack initiation life of welds, ASTM International STP 648, (1978), 134-158

J.Y. Yung, F.V. Lawrence, Analytical and graphical aids for the fatigue design of weldments, Fatigue Fract. Eng. Mater. Struct. 8 (1985), 223-241 crossref(new window)

S. Hong, M.H. Cho, K.B. Kang, Thermal fatigue properties of synthetic heat affected zone in ferritic stainless steel, Journal of KWJS 27 (2009), 79-84 (in Korean)

W.C. Young, R.G. Budynas, Roark's formulas for stress and strain, McGraw-Hill, New York (2002), 771-797

N. Fujita, H.K.D.H. Bhadeshia, M. Kikuchi, Precipitation sequence in niobium-alloyed ferritic stainless steel, Model. Simul. Mater. Sci. Eng. 12 (2004), 273-284 crossref(new window)

N. Fujita, K. Ohmura, M. Kikuchi, T. Suzuki, S. Funaki, I. Hiroshige, Effect of Nb on high-temperature properties for ferritic stainless steel, Scripta Mater. 35 (1996), 705-710 crossref(new window)

C.H. Wells, High Temperature Fatigue, in edited book, Fatigue and microstructure, 1979, American society for metals, metal park, Ohio 44073, 307-333

E.W. Hart, On the role of dislocations in bulk diffusion, Acta Metall. 5 (1957), 597 crossref(new window)