Ferritic Stainless Steels

Author(s): Joseph Ki Leuk Lai, Kin Ho Lo and Chan Hung Shek

Pp: 8-22 (15)

* (Excluding Mailing and Handling)

Abstract

This chapter is on ferritic stainless steels. A brief introduction to the compositions and uses of the various grades of steels in the ferritic class is given. New techniques for grain refinement of the ferritic class are presented. The main problems plaguing the ferritic class, i.e., 475°C-embrittlement, formation of sigma phase and sensitisation, are discussed, with reference to the constitution diagram of the Fe-Cr system. The various theories proposed for the causes of these problems, together with the old and new methods for their alleviation/elimination, are presented in detail.

Keywords: Ferritic stainless steel, sigma phase, sensitisation, 475°C-embrittlement, spinodal decomposition, G phase, constitution diagram, grain refinement, high-temperature embrittlement, intergranular carbide, Cr-depletion theory.