Dissimilar weld joints of P91 and 316LN for power plants Applications-A review

Austenitic stainless steel 316LN and P91 (modified 9Cr 1Mo) ferritic-martensitic steel are being preferred as a structural material in fast breeder reactors, steam generators and prototype fast breeder reactor, These material possess good high temperature mechanical properties, such as tensile strength, creep resistance, toughness, and resistance to oxidation. The welds between these materials were usually welded by using various arc welding processes. Also, when these weld joints operated at high temperatures are mainly subjected to creep phenomenon or creep failures. Both these parameters (i.e. welding and high operating temperatures) lead to creating a lot of heterogeneity in its microstructure and results in degradation of strength in its weld joint over period of time. Therefore, a study is carried out in this paper to highlight the effects of creep behaviour of this dissimilar weld joints at various test conditions and parameters involved.