非调质钢YG1401的冲击韧性和断口形貌探讨

通过采用示波冲击试验机对贝氏体非调质钢YG1401进行系列温度冲击试验,并采用体式显微镜和扫描电镜对断口宏观形貌及微观扩展形貌进行观察,结合示波冲击试验所测的裂纹起裂功及裂纹扩展功研究该材料从24～-80 ℃的冲击断口形貌变化规律.结果 表明:该材料的DBTT为-12℃.试验材料在24～-10℃区间冲击时,材料代表高韧...

Discussion about impact toughness and fracture morphology of #br#non quenched and tempered steel YG1401

The instrumented impact testing machine was employed to perform series of impact tests of bainite non quenched and tempered steel YG1401. The macroscopic morphology and microscopic extension morphology of fracture were observed by optical microscopy and scanning electron microscope. Combined with the crack initiation work and crack extension work measured in instrumented impact test, the evolution law of impact fracture morphology of this materials at 24 -80 ℃ was investigated. The results showed that the ductile brittle transition temperature (DBTT) of such material was -12 ℃. During the impact in range of 24 -10 ℃, the area of stable crack growth zone (which represented the high toughness of material) was the largest. For the impact at -30 ℃, the area of stable crack growth area decreased sharply. With the further decrease of impact temperature, the area of stable crack growth area still decreased gradually. At impact temperature of 24 -10 ℃, the impact fracture morphology was a mixture of coarse tearing edge composed of dense and fine dimples and secondary cleavage with large plastic deformation. With the further decrease of temperature, the radical zone morphology was a mixture of fine tearing edge and primary cleavage.