Quench-hardening testing method and apparatus

A method of testing quench-hardening, comprising the steps of:

• measuring a first size of an annular member before a quench-hardening treatment with respect to at least one of an inner and outer surface of said member;
• measuring a second size of said member after a quench-hardening treatment of said at least one of an inner and outer surface of said member;
• first calculating a difference between said first size and said second size;
• second calculating a quench-hardened distortion ratio by dividing said difference by said first size of said member;
• and
• judging the state of quench-hardening in said member by deciding whether the calculated distortion ratio of said member is within a predetermined range of a distortion ratio of a good quench-hardened member.

A quench-hardening state inspecting apparatus for judging a state of the quench-hardening of a member subjected to quench-hardening treatment in at least one of inner and outer surface of said member, comprising:

• first measuring means for measuring a first size of an annular member before a quench-hardening treatment with respect to at least one of an inner and outer surface of said member;
• second measuring means for measuring a second size of said member after a quench-hardening treatment of at least said one of an inner and outer surface of said member;
• calculating means for determining a difference in said member between said first size and said second size;
• and
• judging means for judging the state of quench-hardening in said member by comparing the difference in said member with a predetermined difference obtained from a good quench-hardened member.

A quench-hardening state inspecting apparatus for judging a state of the quench-hardening of a member subjected to a quench-hardening treatment in at least one of inner and outer surface of said member, comprising:

• first measuring means for measuring a first size of an annular member before a quench-hardening treatment with respect to at least one of an inner and outer surface of said member;
• second measuring means for measuring a second size of said member after a quench-hardening treatment of said at least one of an inner and outer surface of said member;
• first calculating means for determining a difference between said first size and said second size;
• second calculating means for calculating a quench-hardened distortion ratio by dividing said difference by said first size of said member;
• and
• judging means for judging the state of quench-hardening in said member by deciding whether the calculated distortion ratio of said member is within a predetermined range of a distortion ratio of a good quench-hardened member.