节镍无磁不锈钢Cr18Ni6Mn3N的组织及性能

研究了节镍无磁不锈钢Cr18Ni6Mn3N的热轧及固溶后的力学性能和耐蚀性能,分析了其固溶和时效析出后的组织演变规律、冷变形过程中形变诱发马氏体相变及其磁性能.结果表明:该不锈钢的固溶组织为单相奥氏体,其力学性能和耐蚀性能均高于SUS304不锈钢;800℃保温4 h后,在晶界析出粒状氮化物,随着保温时间延长,逐渐沿晶界凸起片层状析出物并向晶内生长,保温20 h后,凸出的片层状析出物直径达20μm.冷轧压下率18.3%时尚未发现形变诱发马氏体组织,随着变形量增大,马氏体含量增多,磁导率上升,但与相同条件下的SUS304不锈钢相比,冷轧板固溶后相对磁导率可降至1.002,因此可用于低成本无磁不锈钢领域.

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.