Forgeabilité des aciers inoxydables austéno-ferritiques

tel-00672279, version 1 - 21 Feb 2012
16 Chapter I. Introduction
For both grades, the as-cast microstructure consists of a ferritic matrix with allotriomorphic austenite
on the grain boundaries and Widmanstätten austenite (γ-Widmanstätten) laths inside the grains, see
Figure I.6.
D1
δ-ferrite
γ-austenite
a) b)
D2
δ-ferrite
γ-austenite
Figure I.6. Microstructures of the as-cast slabs; a) D1 grade; b) D2 grade; γ-austenite in white, δferrite
in grey.
I.2.3 Microstructures during hot rolling
I.2.3.1 The hot rolling process
An industrial hot rolling schedule used for standard duplex stainless steel sheets, i.e. type EN 1.4462
(D1) or 1.4362 is shown in Figure I.7.
1 2 3 4 5
±
Figure I.7. Industrial hot rolling process; the number corresponds to the different steps and some
details are given in the text below.