The Influence Of Specimen Geometry Dimensions And Load On The Local Cleavage Fracture Stress ¦Òf

Experiments were performed on different dimension and different breadth specimen of I6MnR steel , used the three point bend and four point bend load mode at ?96CC to investigate the infection of dimension breadth and load mode to local cleavage fracture stress a ~. This paper used straight notch specimen of CF alloy steel and four point bend and COD specimen of simple iron to research the effect of notch geometry and different specimen form to a ~ , at the same time ,analysis the cleavage fracture mechanism of simple iron which don抰 contain the second phase. The results indicate that: In the scope of about 3mm near the flank of the specimen . it is not satisfied the plane strain ;The critical incident of cleavage fracture of notch specimen is the extend of the micro-crack which is in the size of ferrite crystal; In a certain scatter band, the volume of a ~. is independent to the specimen dimension .. specimen breadth and the load mode, use the specimen of 16.7mm can get the more steady volume of a ~, The cleavage fracture of straight notch specimen is controlled by either the extend condition and the origination condition at ?25 0C, and is controlled by the origination condition at ?96擟; a 1is not affected by dimension of notch and specimen , prove that this parameter is determined by the structure of the material; The difference of the volume of a measured by notch specimen and crack specimen due to the different critical event of them; The respective a ~. volumes of notch specimen and crack specimen are all relatively steady, can be used to the security design in the bug of notch kind or crack kind in engineering material or structure0...