A REVIEW OF EFFECT OF WELDING AND POST WELD HEAT TREATMENT ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF GRADE 91 STEEL

Merchant Samir Y

Abstract: Today getting high thermal efficiency in thermal and nuclear power plant is a big challenge. Many new material are developed. SA 335 grade 91 steel is modified high chrome-moly martenstitic steel. This material is having excellent toughness and high temperature creep strength. During welding, this material is having tremendous change in its microstructure and hence mechanical property. Many research works were done in this area. This paper discusses weld ability of P91 material. Effect of different welding process, type of filler wire, its chemical composition and type of flux is discussed in this paper. PWHT is necessary after welding of P91 steel. PWHT temperature and its duration affects phase transformation and mechanical properties of weld metal, HAZ and parent metal. Major focus is given on hardness, creep resistance and notch toughness

Keywords: P91, Welding, Microstructure, Toughness, Creep, Hardness, PWHT

DOI: https://doi.org/10.15623/ijret.2015.0403096