Selective laser sintering method, heat treatment method, metal powder, and shaped product

Abstract

A selective laser sintering method alternately repeats a step of forming silicon alloy A2 powder (metal powder) in layers, the silicon alloy A2 powder made of high silicon stainless steel containing C:less than 0.10, Si:2.0˜9.0, Mn:0.05˜6.0, Cu:0.5˜4.0, Ni:1.0˜24.0, Cr:6.0˜28.0, Mo:0.2˜4.0, Nb:0.03˜2.0 in wt % and the balance of Fe and inevitable impurities, and a step of selectively applying a laser to the silicon alloy A2 powder formed in layers to melt and sinter the silicon alloy A2 powder.

1 . A selective laser sintering method comprising:
 alternately repeating   a step of forming metal powder in layers, the metal powder being made of high silicon stainless steel containing C:less than 0.10, Si:2.0˜9.0, Mn:0.05˜6.0, Cu:0.5˜4.0, Ni:1.0˜24.0, Cr:6.0˜28.0, Mo:0.2˜4.0, Nb:0.03˜2.0 in wt %, and a balance of Fe and inevitable impurities; and   a step of selectively applying a laser to the metal powder formed in layers to melt and sinter the metal powder.   
     
     
         2 . The selective laser sintering method according to  claim 1 , wherein a particle size of the metal powder is 32 to 62 micrometers. 
     
     
         3 . The selective laser sintering method according to  claim 1 , wherein
 energy density E calculated by following equation is 31 to 124 [J/mm 3 ]   
       
         
           
             
               E 
               = 
               
                 P 
                 
                   v 
                   × 
                   s 
                   × 
                   t 
                 
               
             
           
         
         where P is an output of the laser, v is a scanning speed of the laser, s is a scanning pitch of the laser, and t is a lamination thickness of one layer of the metal powder. 
       
     
     
         4 . The selective laser sintering method according to  claim 3 , wherein the energy density E is 36 to 124 [J/mm 3 ]. 
     
     
         5 . The selective laser sintering method according to  claim 3 , wherein the energy density E is 50 to 124 [J/mm 3 ]. 
     
     
         6 . The selective laser sintering method according to  claim 3 , wherein the energy density E is 50 to 118 [J/mm 3 ]. 
     
     
         7 . A heat treatment method comprising:
 a step of performing solution treatment on a shaped product shaped by the selective laser sintering method according to  claim 1 ; and   a step of performing ageing treatment on the shaped product after the solution treatment.   
     
     
         8 . Metal powder used in a selective laser sintering method that selectively applies a laser to metal powder to melt and sinter the metal powder for lamination, wherein
 the metal powder is made of high silicon stainless steel containing C:less than 0.10, Si:2.0˜9.0, Mn:0.05˜6.0, Cu:0.5˜4.0, Ni:1.0˜24.0, Cr:6.0˜28.0, Mo:0.2˜4.0, Nb:0.03˜2.0 in wt %, and a balance of Fe and inevitable impurities.   
     
     
         9 . The metal powder according to  claim 8 , wherein a particle size of the metal powder is 32 to 62 micrometers. 
     
     
         10 . A shaped product shaped by the selective laser sintering method according to  claim 1 . 
     
     
         11 . A shaped product heat-treated by the heat treatment method according to  claim 7 .