Production method for sintered component made of stainless steel with high corrosion resistance

Abstract

A production method for a sintered component made of stainless steel with high corrosion resistance has steps of preparing a perovskite composite oxide powder made of rare earth element, transition metal element and oxygen, and a stainless steel powder or a mixed powder having a stainless steel composition, mixing the perovskite composite oxide powder and the stainless steel powder or the mixed powder, whereby a raw powder in which the rare earth element is 0.1 to 12 mass % is prepared, compacting the raw powder in a predetermined shape, whereby a green compact is obtained, and sintering the green compact. The sintered component obtained by the production method is a component in which corrosion resistance can be increased without parts of decreasing Cr concentration and precise production processes and process control are not necessary.

1 . A production method for a sintered component made of a stainless steel with high corrosion resistance, comprising the following steps of 
 preparing a perovskite composite oxide powder made of rare earth element, transition metal element and oxygen, and a stainless steel powder or a mixed powder having a stainless steel composition,    mixing the perovskite composite oxide powder and the stainless steel powder or the powder having a stainless steel composition, thereby preparing a raw powder in which the rare earth element is 0.1 to 12 mass %,    compacting the raw powder in a predetermined shape, thereby obtaining a green compact, and    sintering the green compact.    
     
     
         2 . The production method for a sintered component made of a stainless steel with high corrosion resistance according to  claim 1 , wherein the stainless steel powder or the mixed powder having a stainless steel composition contains 11 to 32 mass % of Cr.  
     
     
         3 . The production method for a sintered component made of a stainless steel with high corrosion resistance according to  claim 1 , wherein the stainless steel powder or the mixed powder having a stainless steel composition contains 11 to 32 mass % of Cr and 3.5 to 22 mass % of Ni.  
     
     
         4 . The production method for a sintered component made of a stainless steel with high corrosion resistance according to  claim 1 , wherein the stainless steel powder or the mixed powder having a stainless steel composition contains 11.5 to 18 mass % of Cr and 0.15 to 1.2 mass % of C.  
     
     
         5 . The production method for a sintered component made of a stainless steel with high corrosion resistance according to  claim 2 , wherein the stainless steel powder or the mixed powder having a stainless steel composition contains at least one of 0.3 to 7 mass % of Mo, 1 to 4 mass % of Cu, 0.1 to 5 mass % of Al, 0.3 mass % or less of N, 5.5 to 10 mass % of Mn, 0.15 to 5 mass % of Si, 0.45 mass % or less of Nb, 0.2 mass % or less of P, 0.15 mass % or less of S, and 0.15 mass % or less of Se.  
     
     
         6 . The production method for a sintered component made of a stainless steel with high corrosion resistance according to  claim 3 , wherein the stainless steel powder or the mixed powder having a stainless steel composition contains at least one of 0.3 to 7 mass % of Mo, 1 to 4 mass % of Cu, 0.1 to 5 mass % of Al, 0.3 mass % or less of N, 5.5 to 10 mass % of Mn, 0.15 to 5 mass % of Si, 0.45 mass % or less of Nb, 0.2 mass % or less of P, 0.15 mass % or less of S, and 0.15 mass % or less of Se.  
     
     
         7 . The production method for a sintered component made of a stainless steel with high corrosion resistance according to  claim 4 , wherein the stainless steel powder or the mixed powder having a stainless steel composition contains at least one of 0.3 to 7 mass % of Mo, 1 to 4 mass % of Cu, 0.1 to 5 mass % of Al, 0.3 mass % or less of N, 5.5 to 10 mass % of Mn, 0.15 to 5 mass % of Si, 0.45 mass % or less of Nb, 0.2 mass % or less of P, 0.15 mass % or less of S, and 0.15 mass % or less of Se.  
     
     
         8 . The production method for a sintered component made of a stainless steel with high corrosion resistance according to  claim 1 , wherein the rare earth element is selected from at least one of Sc, Y, La, Ce and Gd.  
     
     
         9 . The production method for a sintered component made of a stainless steel with high corrosion resistance according to  claim 1 , wherein the transition metal element is selected from at least one of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo and W.  
     
     
         10 . The production method for a sintered component made of a stainless steel with high corrosion resistance according to  claim 1 , wherein an average grain diameter of the perovskite composite oxide powder is 30 μm or less.  
     
     
         11 . The production method for a sintered component made of a stainless steel with high corrosion resistance according to  claim 1 , wherein the sintering is performed at a sintering at 1000° C. or more.