Free cutting alloy

Abstract

Provided is free cutting alloy excellent in machinability, preserving various characteristics as alloy. The free cutting alloy contains: one or more of Ti and Zr as a metal element component; and C being an indispensable element as a bonding component with the metal element component, wherein a (Ti,Zr) based compound including one or more of S, Se and Te is formed in a matrix metal phase. The free cutting alloy is more excellent in machinability, preserving various characteristics as alloy at similar levels to a conventional case. The effect is especially conspicuous, for example, when a compound expressed in a chemical form of (Ti,Zr) 4 C 2 (S,Se,Te) 2 as the (Ti,Zr) based compound is formed at least in a dispersed state in the alloy structure.

1 . Free cutting alloy constituted as electromagnetic stainless steel containing:
 2.0 to 3, the upper and lower limits not included, mass % Si;   2 mass % or lower Mn;   5 to 25 mass % Cr;   0.01 to 0.020, the lower limit not included, mass % Al;   one or more of Ti and Zr so that X defined by the following formula 1 is in the range of 0.05 to 0.5 mass %;   C in the range of 0.19x to 0.26x mass %, wherein X is expressed by the following formula 1;   one or more of S, Se and Te so that the value Y is greater than or equal to −2.72C+0.68X mass %, is greater than or equal to (Z−0.047)X mass %, is less than or equal to (Z+0.07)X mass %, and is equal to or less than 0.43X mass %, wherein X, Z and Y are values of the respective following formulae 1, 3 and 2;
   Ti %+0.52Zr %= X   (Formula 1) 
   S %+0.41Se %+0.25Te %= Y   (Formula 2) 
   32(C %/X−0.125) 2   =Z   (Formula 3) 
   Fe being the main component of the alloy;   inevitable impurities;   and wherein a (Ti,Zr) based compound containing one or more of Ti and Zr as a metal element component, C being an indispensable element as a bonding component with the metal element component, and one or more of S, Se and Te is dispersed in a matrix metal phase.   
     
     
         2 . Free cutting alloy according to  claim 1  further containing one or more selected from the group consisting of Ni, Cu, Mo, Nb and V in the respective ranges of 2 mass % or lower for Ni; 2 mass % or lower for Cu; 2 mass % or lower for Mo; 1 mass % or lower for Nb and 1 mass % or lower for V. 
     
     
         3 . Free cutting alloy according to  claim 1  further containing one or more selected from the group consisting of Pb, B and metal elements classified as Group 3A in the periodic table of elements in the respective ranges of 0.15 mass % or lower for Pb, 0.01 mass % or lower for B; and 0.1 mass % or lower for one or more of metal elements classified as Group 3A in the periodic table of elements in total. 
     
     
         4 . Free cutting alloy according to  claim 1  further containing one or more selected from the group consisting of Ni, Cu, Mo, Nb and V in the respective ranges of 2 mass % or lower for Ni; 2 mass % or lower for Cu; 2 mass % or lower for Mo; 1 mass % or lower for Nb and 1 mass % or lower for V; and
 further containing one or more selected from the group consisting of Pb, B and metal elements classified as Group 3A in the periodic table of elements in the respective ranges of 0.15 mass % or lower for Pb, 0.01 mass % or lower for B; and 0.1 mass % or lower for one or more of metal elements classified as Group 3A in the periodic table of elements in total.   
     
     
         5 . Free cutting alloy constituted as electromagnetic stainless steel containing:
 0.01 to 2.0 mass % Si;   2 mass % or lower Mn;   5 to 25 mass % Cr;   0.030 to 5 mass % Al;   one or more of Ti and Zr so that X defined by the following formula 1 is in the range of 0.05 to 0.5 mass %;   C in the range of 0.19x to 0.26x mass %, wherein X is expressed by the following formula 1;   one or more of S, Se and Te so that the value Y is greater than or equal to −2.72C+0.68X mass %, is greater than or equal to (Z−0.047)X mass %, is less than or equal to (Z+0.07)X mass %, and is equal to or less than 0.43X mass %, wherein X, Z and Y are values of the respective following formulae 1, 3 and 2;
   Ti %+0.52Zr % X  (Formula 1) 
   S %+0.41Se %+0.25Te %= Y   (Formula 2) 
   32(C %/X−0.125) 2   =Z   (Formula 3) 
   Fe being the main component of the alloy;   inevitable impurities;   and wherein a (Ti,Zr) based compound containing one or more of Ti and Zr as a metal element component, C being an indispensable element as a bonding component with the metal element component, and one or more of S, Se and Te is dispersed in a matrix metal phase.   
     
     
         6 . Free cutting alloy according to  claim 5  further containing one or more selected from the group consisting of Ni, Cu, Mo, Nb and V in the respective ranges of 2 mass % or lower for Ni; 2 mass % or lower for Cu; 2 mass % or lower for Mo; 1 mass % or lower for Nb and 1 mass % or lower for V. 
     
     
         7 . Free cutting alloy according to  claim 5  further containing one or more selected from the group consisting of Pb, B and metal elements classified as Group 3A in the periodic table of elements in the respective ranges of 0.15 mass % or lower for Pb, 0.01 mass % or lower for B; and 0.1 mass % or lower for one or more of metal elements classified as Group 3A in the periodic table of elements in total. 
     
     
         8 . Free cutting alloy according to  claim 5  further containing one or more selected from the group consisting of Ni, Cu, Mo, Nb and V in the respective ranges of 2 mass % or lower for Ni; 2 mass % or lower for Cu; 2 mass % or lower for Mo; 1 mass % or lower for Nb and 1 mass % or lower for V; and
 further containing one or more selected from the group consisting of Pb, B and metal elements classified as Group 3A in the periodic table of elements in the respective ranges of 0.15 mass % or lower for Pb, 0.01 mass % or lower for B; and 0.1 mass % or lower for one or more of metal elements classified as Group 3A in the periodic table of elements in total.   
     
     
         9 . Free cutting alloy constituted as electromagnetic stainless steel containing:
 2.0 to 3, the upper and lower limits not included, mass % Si;   2 mass % or lower Mn;   5 to 25 mass % Cr;   0.01 to 0.020, the lower limit not included, mass % Al;   one or more of Ti and Zr so that X defined by the following formula 1 is in the range of 0.05 to 0.5 mass %;   C in the range of 0.02× to 0.26x mass %, wherein X is expressed by the following formula 1;   one or more of S, Se and Te so that the value Y is greater than or equal to 2.72 C mass % when C/X is less than 0.125, is greater than or equal to −2.72C+0.68X mass % when C/X is greater than 0.125, is less than or equal to 0.43X mass %, and is greater than or equal to (Z+0.07)X, wherein X, Z and Y are values of the respective following formulae 1, 3 and 2;
   Ti %+0.52Zr %= X   (Formula 1) 
   S %+0.41Se %+0.25Te %= Y   (Formula 2) 
   32(C %/X−0.125) 2   =Z   (Formula 3) 
   Fe being the main component of the alloy;   inevitable impurities;   wherein Pb content is less than 0.01 mass %;   and wherein a (Ti,Zr) based compound containing one or more of Ti and Zr as a metal element component, C being an indispensable element as a bonding component with the metal element component, and one or more of S, Se and Te is dispersed in a matrix metal phase.   
     
     
         10 . Free cutting alloy according to  claim 9  further containing one or more selected from the group consisting of Ni, Cu, Mo, Nb and V in the respective ranges of 2 mass % or lower for Ni; 2 mass % or lower for Cu; 2 mass % or lower for Mo; 1 mass % or lower for Nb and 1 mass % or lower for V. 
     
     
         11 . Free cutting alloy according to  claim 9  further containing one or more selected from the group consisting of B and metal elements classified as Group 3A in the periodic table of elements in the respective ranges of 0.01 mass % or lower for B; and 0.1 mass % or lower for one or more of metal elements classified as Group 3A in the periodic table of elements in total. 
     
     
         12 . Free cutting alloy according to  claim 9  further containing one or more selected from the group consisting of Ni, Cu, Mo, Nb and V in the respective ranges of 2 mass % or lower for Ni; 2 mass % or lower for Cu; 2 mass % or lower for Mo; 1 mass % or lower for Nb and 1 mass % or lower for V; and
 further containing one or more selected from the group consisting of B and metal elements classified as Group 3A in the periodic table of elements in the respective ranges of 0.01 mass % or lower for B; and 0.1 mass % or lower for one or more of metal elements classified as Group 3A in the periodic table of elements in total.   
     
     
         13 . Free cutting alloy constituted as electromagnetic stainless steel containing:
 0.01 to 2.0 mass % Si;   2 mass % or lower Mn;   5 to 25 mass % Cr;   0.030 to 5 mass % Al;   one or more of Ti and Zr so that X defined by the following formula 1 is in the range of 0.05 to 0.5 mass %;   C in the range of 0.02× to 0.26x mass %, wherein X is expressed by the following formula 1;   one or more of S, Se and Te so that the value Y is greater than or equal to 2.72 C mass % when C/X is less than 0.125, is greater than or equal to −2.72C+0.68X mass % when C/X is greater than 0.125, is less than or equal to 0.43X mass %, and is greater than or equal to (Z+0.07)X, wherein X, Z and Y are values of the respective following formulae 1, 3 and 2;
   Ti %+0.52Zr %= X   (Formula 1) 
   S %+0.41Se %+0.25Te %= Y   (Formula 2) 
   32(C %/X−0.125) 2   =Z   (Formula 3) 
   Fe being the main component of the alloy;   inevitable impurities;   wherein Pb content is less than 0.01 mass %;   and wherein a (Ti,Zr) based compound containing one or more of Ti and Zr as a metal element component, C being an indispensable element as a bonding component with the metal element component, and one or more of S, Se and Te is dispersed in a matrix metal phase.   
     
     
         14 . Free cutting alloy according to  claim 13  further containing one or more selected from the group consisting of Ni, Cu, Mo, Nb and V in the respective ranges of 2 mass % or lower for Ni; 2 mass % or lower for Cu; 2 mass % or lower for Mo; 1 mass % or lower for Nb and 1 mass % or lower for V. 
     
     
         15 . Free cutting alloy according to  claim 13  further containing one or more selected from the group consisting of B and metal elements classified as Group 3A in the periodic table of elements in the respective ranges of 0.01 mass % or lower for B; and 0.1 mass % or lower for one or more of metal elements classified as Group 3A in the periodic table of elements in total. 
     
     
         16 . Free cutting alloy according to  claim 13  further containing one or more selected from the group consisting of Ni, Cu, Mo, Nb and V in the respective ranges of 2 mass % or lower for Ni; 2 mass % or lower for Cu; 2 mass % or lower for Mo; 1 mass % or lower for Nb and 1 mass % or lower for V; and
 further containing one or more selected from the group consisting of B and metal elements classified as Group 3A in the periodic table of elements in the respective ranges of 0.01 mass % or lower for B; and 0.1 mass % or lower for one or more of metal elements classified as Group 3A in the periodic table of elements in total.