关键词: 材料合成与加工工艺, 激光, 裂纹槽, 单边裂纹轴向拉伸试样, 连杆, 裂解, 等效临界应力强度因子

Abstract:

The tensile test was done for the axial tensile specimen with single edge crack notch processed by laser. The specimen was sampled from the connecting rod blank forged by the high-carbon micro-alloyed non-hardening-and-tempering steel(S70S6). The influence of the laser processed single edge notch on the tensile fracture of specimen was analyzed, and the fractography and the fracture load of the specimen with the laser notch were compared with the specimens with the notches processed by wire cut electrical discharge(WEDM) and broaching. The results show that the specimen with laser notch was characterized by the smallest notch tip plastic deformation region, it can be fractured by the smallest axial tensile load which is about 20% and 30% smaller than that of the specimen with WEDM notch and broaching notch, respectively. The equivalent critical stress intensity factor was defined based on the test results which is 25.51 MPa·m^1/2.The results provide a reference for the load parameter calculation of the fracture splitting connecting rod with starting notch processed by laser.

Key words: materials synthesis and process technology, laser, notch, axial tensile specimen with single edge crack, connecting rod, fracture splitting, equivalent critical stress intensity factor