| 摘要 |
PURPOSE:To observe generation and growth of a crack accompanying to the thermal stress even if a material having relatively large thermal expansion coefft. is used as the testing part by using a material having a thermal expansion coefft. smaller than that of the testing part as a material of the sticking part provided at the testing part. CONSTITUTION:The sticking part 11 made of ferrite metal having a small thermal expansion coefft. are welded at both sides of the testing part 15 having a constricted part 14 and made of e.g. austenite stainless steel having a large thermal expansion coefft. and said welded body is used as a testing piece 18. Loading members 12 made of austenite stainless steel having a large thermal expansion coefft. are welded to two sticking parts 11 symmetrically on right and left and the test piece is composed. If the test piece is heated, although the part 15 of the piece 18 and the members 12 are expanded at the same thermal expansion coefft., a tensile thermal stress 16 can be applied to the part 15 basing on the thermal expansion difference between the part 11 and the member 12, since the member 12 is stuck to the part 15 through the part 11 having a low thermal expansion coefft. Generation and growth of the crack accompanying to the thermal stress is observed continuously. |
