Welding Metallurgy of Ferritic Stainless Chromium Steels with Carbon Contents Below 0.15%

Abstract

Depending upon the alloying contents of chromium, nickel and carbon which are present in stainless steels, the structure after cooling to ambient temperature will consist of varying amounts of delta ferrite, austenite and martensite. Table 12 shows average values of the typical analysis of some weldable chromium steels, the carbon content of which has been set below 0.15% in order to improve the weldability. There are two main groups of steel, one with 12% and the other with 17% chromium, which differ mainly with regard to their corrosion resistance. With the addition of 1–2% molybdenum, the pitting resistance and retention of hardness can be improved. The corrosion behaviour of these grades, with special consideration towards welding is discussed by Bäumel [206, 207, 227] and by Honeycombe and Gooch [361].