| 摘要 |
PURPOSE:To male it possible to obtain tensile strength with high reliability by calculating an index value from the acoustic velocity ratio and carbon percentage of casting and steel, calculating a hardness factor from the index value and the tensile strength from the hardness factor and hardness. CONSTITUTION:A main program 550 actuates other programs to control the implementing sequence thereof. A steel acoustic velocity setting program 511 sets the acoustic velocity of a steel material to a memory region Vm. Next, the carbon percentage of a casting 1a to be inspected is inputted and set to a memory region C through a key board 7. An acoustic velocity measuring program 51 is activated to obtain the acoustic velocity in a memory region V and an acoustic velocity normalizing program 512 calculates the ratio of the acoustic velocity V of the casting 1a to the steel acoustic velocity Vm and sets the ratio to a memory region V/Vm. Also, the hardness of the casting 1a is set to a memory region HB through the key board 7. A tensile strength calculating program 540 is activated to calculate an index value alpha' from the acoustic velocity ratio V/Vm and carbon percentage C according to an alpha' calculating procedure 540a and a hardness factor m' from alpha' according to an m' calculating procedure 540b. The tensile strength sigmaB' of the casting 1a to be inspected is figured out of the hardness factor m' and Brinnel hardness HB according to a sigmaB' calculating procedure 540c. |
