Research on Effects of Internal Quality of Casting Blank on DWTT(Drop Weight Tear Test)Properties of Heavy Gauge X80M Hot Rolled Steel Strip
The drop weight tear test(DWTT)is used to test the toughness of materials,mainly for studying the low-temperature toughness of metal materials.In the paper,the microstructure and morphology of samples corresponding to dif-ferent area proportions of brittle fracture are compared and analyzed with optical microscope aiming at the unqualified DWTT properties of products during trial production process of heavy gauge X80M hot rolled steel strip.The composition segrega-tion in thickness direction of casting blank is tested.It is found that the severe segregation in thickness direction of steel strip is the main factor influencing the DWTT properties by analysis.The center segregation of casting blank and DWTT properties of product are improved effectively by adjusting the arc alignment precision of segment and optimizing the specific water amount of continuous casting machine so that the goal of stable production of hot rolled steel strip for heavy gauge X80M pipeline steel is realized.