Method of making stainless steel

Abstract

A method of making stainless steel includes smelting metal material and atomizing and powdering the smelted metal material to obtain a first alloy powder, detecting a mass fraction of manganese in the first alloy powder, heating and kneading the first alloy powder with plastic, and granulating, injection molding, and sintering the first alloy powder kneaded with plastic to obtain stainless steel. If the mass fraction of manganese in the first alloy powder is less than 12%, before heating and kneading with plastic, a predetermined amount of manganese-containing material is added to the first alloy powder to obtain a second alloy powder having a mass fraction of manganese of 12-15%.

What is claimed is: 
     
         1 . A method of making stainless steel, the method comprising:
 smelting metal material and atomizing and powdering the smelted metal material to obtain a first alloy powder;   heating and kneading the first alloy powder with plastic; and   granulating, injection molding, and sintering the first alloy powder kneaded with plastic to obtain stainless steel.   
     
     
         2 . The method of  claim 1 , wherein before heating and kneading the first alloy powder with plastic, the method further comprising:
 detecting a mass fraction of manganese in the first alloy powder;   if the mass fraction of manganese in the first alloy powder is less than 12%, adding a predetermined amount of manganese-containing material to the first alloy powder to obtain a second alloy powder having a mass fraction of manganese of 12-15%.   
     
     
         3 . The method of  claim 2 , wherein:
 the manganese-containing material comprises at least one of pure manganese, manganese iron powder, or other manganese-containing compound.   
     
     
         4 . The method of  claim 2 , wherein:
 a mass percentage of the plastic relative to the first alloy powder is 6-10%.   
     
     
         5 . The method of  claim 2 , wherein:
 a mass fraction of chromium in the second alloy powder is 15.5-17.5%.   
     
     
         6 . The method of  claim 2 , wherein:
 a mass fraction of molybdenum in the second alloy powder is 3-4%.   
     
     
         7 . The method of  claim 2 , wherein:
 a mass fraction of nickel in the second alloy powder is not more than 0.2%.   
     
     
         8 . The method of  claim 2 , wherein:
 a mass fraction of silicon in the second alloy powder is not more than 1%.   
     
     
         9 . The method of  claim 2 , wherein:
 a total mass fraction of phosphorus, sulfur, carbon, oxygen, and nitrogen in the second alloy powder is not more than 1%.   
     
     
         10 . The method of  claim 2 , wherein:
 particles obtained from granulation are cylindrical and have a diameter of 2-5 mm and a length of 3-6 mm.   
     
     
         11 . The method of  claim 2 , wherein:
 the plastic is polyoxymethylene.   
     
     
         12 . A method of making stainless steel, the method comprising:
 smelting metal material and atomizing and powdering the smelted metal material to obtain a first alloy powder;   detecting a mass fraction of manganese in the first alloy powder;   if the mass fraction of manganese in the first alloy powder is less than 12%, adding a predetermined amount of manganese-containing material to the first alloy powder to obtain a second alloy powder having a mass fraction of manganese of 12-15%;   heating and kneading the first alloy powder or the second alloy powder with plastic;   and granulating, injection molding, and sintering the first alloy powder or the second alloy powder kneaded with plastic to obtain stainless steel.   
     
     
         13 . The method of  claim 12 , wherein:
 the manganese-containing material comprises at least one of pure manganese, manganese iron powder, or other manganese-containing compound.   
     
     
         14 . The method of  claim 12 , wherein:
 a mass percentage of the plastic relative to the first alloy powder is about 6-10%.   
     
     
         15 . The method of  claim 12 , wherein:
 a mass fraction of chromium in the second alloy powder is 15.5-17.5%.   
     
     
         16 . The method of  claim 12 , wherein:
 a mass fraction of molybdenum in the second alloy powder is 3-4%.   
     
     
         17 . The method of  claim 12 , wherein:
 a mass fraction of nickel in the second alloy powder is not more than 0.2%.   
     
     
         18 . The method of  claim 12 , wherein:
 a mass fraction of silicon in the second alloy powder is not more than 1%.   
     
     
         19 . The method of  claim 12 , wherein:
 a total mass fraction of phosphorus, sulfur, carbon, oxygen, and nitrogen in the second alloy powder is not more than 1%.   
     
     
         20 . The method of  claim 12 , wherein:
 particles obtained from granulation are cylindrical and have a diameter of 2-5 mm and a length of 3-6 mm; and   the plastic is polyoxymethylene.