Microstructure and properties of nickle-saving nonmagnetic Cr18Ni6Mn3N stainless steel

The mechanical properties and corrosion resistance of nickle-saving nonmagnetic Cr18Ni6Mn3N stainless steel were studied after hot rolling and solution heat treatment.The microstructural evolution after solution heat treatment and aging treatment,the variation trend of deformation induced by martensite during cold working,and the magnetic property of the stainless steel were analyzed.The results indicate that single austenitic phase appears in the stainless steel at room temperature after solution heat treatment.Compared with SUS304 stainless steel,the mechanical properties and corrosion resistance of the stainless steel are better.Granular nitrides precipitate along grain boundaries after a 4h holding time at 800℃;however,when the holding time prolongs,lamellar precipitates begin to emboss along grain boundaries and then grow into grains.After a 20h holding time,the diameter of the embossed lamellar precipitates reaches to 20 μm.Deformation-induced martensite does not appear at a reduction rate of 18.3%,and with increasing deformation the amount of martensite gradually increases.Although the relative magnetic conductivity rises,it is less than that of SUS304 stainless steel under the same condition.After solution heat treatment the relative magnetic conductivity of the cold rolled plate drops to 1.002,and thus the stainless steel can be a low-cost candidate in the nonmagnetic stainless steel field.