The influence of weld thermal cycles on the microstructure and toughness of duplex stainless steels
- Edison Welding Inst., Columbus, OH (United States)
- Ohio State Univ., Columbus, OH (United States)
Duplex stainless steels have gained significant usage due to their excellent combination of mechanical properties and corrosion resistance. These properties are achieved through a microstructural balance that is approximately 50% ferrite and 50% austenite. Yield strengths are almost 50% higher than the austenitic stainless steels and the corrosion resistance, particularly the pitting and stress corrosion cracking resistance, is significantly better than that of the austenitic stainless steels. Base material microstructure balances are obtained through a combination of composition control and heat treatment. However, the microstructure of the weld metal as well as the heat-affected zone (HAZ) cannot generally be modified by postweld annealing since these weldments may not be amenable to postweld heat treatment. Weld metal microstructures are generally controlled by adjusting the composition of the deposit. This usually means that the weld metal composition is enhanced with austenite formers such as nickel and nitrogen. The HAZ on the other hand, has its microstructure modified primarily through the thermal cycle that it experiences. The thermal cycle and, hence, the cooling rate, is governed in turn, by the heat input of the welding process. This paper reviews research conducted at the Edison Welding Institute (EWI) and The Ohio State University (OSU) to address this issue. Fundamental studies utilizing Gleeble simulation have been conducted to understand the microstructural evolution as a function of cooling rate and its influence on the HAZ toughness. Also, the autogenous gas tungsten arc (GTA) process has been used to understand the influence of heat input on the microstructural evolution in the fusion zone as well as in the HAZ.
- OSTI ID:
- 27946
- Report Number(s):
- CONF-940230-; ISBN 0-7918-1266-9; TRN: IM9516%%72
- Resource Relation:
- Conference: 13. international conference on offshore mechanics and Arctic engineering (OMAE-13), Houston, TX (United States), 27 Feb - 3 Mar 1994; Other Information: PBD: 1994; Related Information: Is Part Of OMAE 1994. Volume 3: Materials Engineering; Salama, M.M.; Toyoda, Masao; Lui, S.; Dos Santos, J.F.; Kocak, M.; Patterson, E.A.; Berge, S. [eds.]; PB: 438 p.
- Country of Publication:
- United States
- Language:
- English
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