The low temperature magnetic properties of austenitic Fe-Cr-Ni alloys

On the cryogenic magnetic transition and martensitic transformation of the austenite phase of 7MoPLUS duplex stainless steel

“…It has been established that AusSSs may behave as a superparamagnet [31], a spin glass [32], a ferromagnet [32] or an antiferromagnet [4][5][6]32]. The austenite of 7MoPLUS is believed to be antiferromagnetic.…”

“…Studies on the cryogenic magnetic properties of both ferritic stainless steels (FSSs) [3] and austenitic stainless steels (AusSSs) [4][5][6] have already been published. It is well established that FSSs remain ferromagnetic at cryogenic temperatures, whereas some AusSSs will transform magnetically or martensitically [7].…”

“…In regard to the cryogenic magnetic behaviour of AusSSs, a number of very good empirical expressions for estimating their Neel temperature (T Neel ) [5,8] and martensitic point (Ms) [5,[9][10][11][12][13][14][15] have been proposed. For the estimation of Ms, inasmuch as the 'old' expressions [5,[9][10][11][12] were developed on rather narrow composition ranges, research is still on-going with an eye to considering the effects of more alloying elements [13][14][15] and their interactions [15].…”

“…For the estimation of Ms, inasmuch as the 'old' expressions [5,[9][10][11][12] were developed on rather narrow composition ranges, research is still on-going with an eye to considering the effects of more alloying elements [13][14][15] and their interactions [15].…”

“…While these 'old' [5,[9][10][11][12] and new [13][14][15] expressions have been shown to be well suited for use with AusSSs, their applicability to the austenite phase of DSSs has never been ascertained. It has to be stressed that it might be inappropriate to simply view the austenite phase of DSSs as ordinary, singlephased AusSSs, because the austenite of DSSs is surrounded by ferrite.…”