遷移温度域における脆性破壊起点に関する考察

概要

論文の詳細を見る
The fracture toughness test and the partially loaded and unloaded tests were conducted for Ni-Cr-Mo-V steel at the transition temperature. Stereographic observation of SEM (Scanning Electron Microscope) photographs was conducted on the fracture surface of the test specimen to measure both the amount of microscopic tearing crack extension and the distance from the originating site of brittle fracture, measured from the tip of the tearing crack. Elastic stress distribution around the crack tip was also discussed. It was concluded that the microscopic tearing crack initiates when the stress intensity exceeds the plane strain fracture toughness, and that the originating site of brittle fracture is situated slantwise and forward from the crack tip. The stress intensity of a postulated microcrack ahead of the tearing crack was found to reach the maximum value at this site. The formerly proposed procedure for the modified J_<IC> test to determine the initiation of the microscopic tearing crack was proven to be effective.
一般社団法人日本機械学会の論文
1988-02-25