Guidelines for Specification and Measurement of Ferrite in Austenitic Stainless Steel Weld Metal

The experience of the 1940s demonstrated beyond doubt the connection between the presence at room temperature of a small amount of ferrite in an otherwise austenitic weld deposit and the absence of cracking or even microfissuring in that weld deposit. With the publication of the Schaeffler Diagram in 1948, one might have expected all cracking and microfissuring difficulties with these weld metals to vanish. However, it should be noted that Schaeffler claimed no better than ±4% ferrite accuracy.