Austenitic series stainless steel and relevant casting method

Abstract

An austenitic series stainless steel and relevant casting method mainly comprises procedures of a preparation, a heat, a refinement, and a formation; wherein the present method mainly applies cheap scraps of stainless steels with about 13 to 18 wt % chromium basic to the manufacture. Further, the element manganese is used to substitute nickel and thence the proportion of nitrogen is increased while manufacturing. Accordingly, a component of the austenitic stainless steel of the present invention contains less than 0.08 wt % carbon, less than 0.9 wt % silicon, about 13 to 19 wt % manganese, less than 0.04 wt % phosphorus, less than 0.04 wt % sulfur, about 13 to 18 wt % chromium, less than 0.1 wt % nickel, less than 0.8 wt % nitrogen, and essentially iron and residuals. Such inclusion assists the austenitic stainless steel to attain same properties of preferable corrosion resistance and mechanism behaviors as those of the typical 300 series stainless steel.

1 . A casting austenitic series stainless steel, having a composition in weight (wt %) comprising:
 a) less than 0.08 wt % carbon (C);   b) less than 0.9 wt % silicon (Si);   c) about 13 wt % to about 19 wt % manganese (Mn);   d) less than 0.04 wt % phosphorus (P);   e) less than 0.04 wt % sulfur (S);   f) about 13 wt % to about 18 wt % chromium (Cr);   g) less than 0.1 wt % nickel (Ni);   h) less than 0.8 wt % nitrogen (N); and   i) balance essentially iron (Fe) and other residual elements.   
     
     
         2 . A method of manufacturing a casting austenitic stainless steel, comprising steps of:
 a) preparing scraps of stainless steels, with the inclusion of chromium (Cr) from about 13 wt % to 18 wt %, wherein, said scraps being mixed with each other to become an admixture;   b) placing and heating said admixture inside an open high-frequency furnace and fusing said admixture into liquid steel; appending elements of nitrogen (N) and manganese (Mn) into said liquid steel to contain less than 0.8 wt % nitrogen (N) therein for maintaining a corrosion resistance thereof, and to include about 13 wt % to 19 wt % manganese (Mn) therein for obviating magnetic properties thereof;   c) removing impurities to refine said liquid steel into pure liquid steel; sampling and analyzing said pure liquid steel to prove actual rates among a component of said pure liquid steel, and comparing said actual component with said anticipated component claimed in  claim 1  to add insufficient parts of said actual component in proportion to said anticipated component; and   d) infusing said pure liquid steel consisted of said anticipated component into a mold and coagulating said pure liquid steel into a solid stainless steel; releasing said solid stainless steel from said mold and thus accomplishing a formation of said austenitic series stainless steel.   
     
     
         3 . The method as claimed in  claim 2 , wherein said high-frequency furnace has a temperature at the range preferably from 1650 degree C. to 1750 degree C.