HIGH TEMPERATURE REFERENCE WORKPIECE AND ACCURACY VERIFICATION METHOD FOR HIGH TEMPERATURE OBJECT DIMENSION MEASURING SHAPE MEASUREMENT INSTRUMENT USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a high temperature reference workpiece used for a reference workpiece for measuring a dimension in a high temperature environment as hot forging, and an accuracy verification method for a high temperature object dimension measuring shape measurement instrument using the reference workpiece.;SOLUTION: The high temperature reference workpiece is obtained by a high-melting point metal material having a plurality of half-circle-shaped cross sections juxtaposed in one direction at a regular spacing, a known thermal expansion coefficient and an oxidation resistance. A surface shape dimension as a theoretical value at a high temperature is obtained from measurement values of the thermal expansion coefficient of the reference workpiece and the surface shape dimension of the half-circle-shaped cross sections in the juxtaposed direction at a normal temperature. The reference workpiece is heated to the high temperature as a verification target. A noncontact shape measurement instrument measures the surface shape dimension as an object of the accuracy verification. A circular fitting process is implemented in a plurality of the half-circle-shaped cross sections within a surface shape. The surface shape dimension is obtained as an actually-measured value. The accuracy of the high temperature object dimension measuring shape measurement instrument is verified by obtaining a comparison value of the actually-measured value and the theoretical value.;COPYRIGHT: (C)2010,JPO&INPIT