FIG. 35 WRC-1992 DIAGRAM PREDICTING FERRITE CONTENT IN STAINLESS STEELS. FERRITE CONTENT ISGIVEN BY THE FERRITE NUMBER (FN), WHERE 100 FN IS APPROXIMATELY EQUAL TO 65 VOL% FERRITE.BOUNDARIES DENOTING A CHANGE IN SOLIDIFICATION MODE (A, AF, FA AND F PER FIG. 34) ARE ALSOSHOWN (INDICATED BY DOTTED LINES). SOURCE: REF 45

It is a fortunate coincidence that the coefficients in the Creq and Nieq expressions (see Fig. 35), which have been obtainedby statistical fitting methods, result in satisfactory correlations with both the solidification mode and the ferrite number (aprecisely measurable quantity that is roughly proportional to the actual volume percentage of ferrite at room temperature)(Ref 44). Indeed, it has been found that the same Creq and Nieq expressions (that is, with the same elements andcoefficients) are not able to satisfactorily fix the locations of the martensite and martensite-austenite phase fields seen inthe lower left region of the Schaeffler diagram. For this reason, such regions of Creq and Nieq are excluded in the WRC-1992 diagram.

A discussion of weld decay due to sensitization and knife line attack in the HAZ of austenitic stainless steels can be foundin Ref 14 and 46.

References cited in this section

14. S. KOU, WELDING METALLURGY, JOHN WILEY & SONS, 198743. J.A. BROOKS AND A.W. THOMPSON, MICROSTRUCTURAL DEVELOPMENT AND

SOLIDIFICATION CRACKING SUSCEPTIBILITY OF AUSTENITIC STAINLESS STEEL WELDS,INT. MATER. REV., VOL 36 (NO. 1), 1991

44. T.A. SIEWERT, C.N. MCCOWAN, AND D.L. OLSON, FERRITE NUMBER PREDICTION TO 100 FNIN STAINLESS STEEL WELD METAL, WELD. J., DEC 1988, P 289S-298S

45. D.J. KOTECKI AND T.A. SIEWERT, WRC-1992 CONSTITUTION DIAGRAM FOR STAINLESSSTEEL WELD METALS: A MODIFICATION OF THE WRC-1988 DIAGRAM, WELD. J., MAY 1992, P171S-178S

46. T.G. GOOCH AND D.C. WILLINGHAM, WELD DECAY IN AUSTENITIC STAINLESS STEELS, THE