PURPOSE: To make mechanical working of a test piece unnecessary and to simplify and expedite remarkably a judgement of mechanical properties of a steel material by measuring substituted values such as hardness, grain size, and components of the steel material, and judging mechanical characteristics based on these measured values.
CONSTITUTION: After measuring hardness, grain size and chemical component, etc. of the steel material by suitable means, tensile strength, yield value are obtained by using values of grain size and component together with hardness as a center to correct the work hardening characteristic, and elongation is obtained by using a shape size of the tensile test piece to values of hardness, grain size and component. A shelf energy and a transition temp. are obtained by using values of hardness, grain size and component. An energy and transition temp. curve is divided to regions of ductility, transition and brittleness and values of the shelf energy and the transition temp. are used to convert to an approximated numerical formula, and an absorption energy in an arbitrary temp. is obtained. In such a way, mechanical characteristic values are judged from measuring hardness, grain size and components of the steel material, instead of tensile test and impacting test.
SEKIGUCHI SHIYOUICHI
ISHIDA TSUGIO
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