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)4C2(S,Se,Te)2 as the (Ti,Zr) based compound is formed at least in a dispersed state in the alloy structure.

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)4C2(S,Se,Te)2 as the (Ti,Zr) based compound is formed at least in a dispersed state in the alloy structure.

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)4C2(S,Se,Te)2 as the (Ti,Zr) based compound is formed at least in a dispersed state in the alloy structure.

Abstract: A free-cutting tool steel is provided containing Fe and C in an amount of 0.1 to 2.5 wt %, Ti and or Zr where WTi+0.52WZr constitutes 0.03 to 3.5 wt %, and WTi represents Ti content and WZr represents Zr content, at least any one of S, Se and Te where WS+0.4WSe+0.25WTe constitutes 0.01 to 1.0 wt %, and (WTi+0.52WZr)/(WS+0.4WSe+0.25WTe) constitutes 1 to 4, and WS represents S content, WSe represents Se content and WTe represents Te content; and dispersed therein a texture thereof from 0.1 to 10% in terms of area ratio in a section of a machinability improving compound phase of a metallic element component of Ti and/or Zr as major components, and a binding component for the metallic element component containing C and any one of S, Se and Te.