Toughness of Austenitic Castings

Perdomo, J. J. (Welding and Metallurgy Specialist) | Morales, I. A. (Inspection Specialist) | Houben, John J. (Fabrication Specialist)

OnePetro 

ABSTRACT

The influence of ferrite and heat treatment condition on the toughness of ASTM(1) A 351 Grade CF3M (0.03C-19Cr-9Ni-2Mo) and CF8M (0.08C-19Cr-9Ni-2Mo) castings used in valve bodies in both Cold -200F

BACKGROUND

ExxonMobil(2) completed a study of the influence of ferrite and heat treatment condition on the toughness of ASTM A 351 Grade CF3M (0.03C-19Cr-9Ni-2Mo) and CF8M (0.08C-19Cr-9Ni-2Mo) castings used in valve bodies in both Cold -200F1,2 can be used on ASTM A 351 Grade CF3M and CF8M castings3. The ASME(3) B31.3 Code4 accepts A 351 CF3M and CF8M material down to -425F (- 255C) in low temperature toughness applications, as long as the cited material contains C<0.1%w, and it’s the annealed condition. There is no mentioning of ferrite content to influence toughness. Additionally, no details of the heat treatment condition are provided for these materials to be acceptable for low-temperature, acceptable toughness applications. When the Code requires toughness measurements on austenitic stainless steels at a targeted temperature, it is expressed in terms of lateral expansion with a minimum of 0.015 in (0.4 mm) per Charpy V-notch tests carried in accordance with ASTM A 3705