铸坯在加热炉停留时间对中厚板探伤合格率的影响

对连铸板坯在炉停留时间和热轧中厚板超声波探伤质量之间的关系进行了研究.结果表明:220mm厚连铸板坯在炉停留时间低于3h会导致中厚板超声波探伤合格率显著降低;延长铸坯在炉停留时间能够有效提高中厚板的超声波探伤合格率;中厚板中引起超声波探伤不合的缺陷是珠光体带中的微裂纹;减弱连铸板坯的中心线偏析能够有效提高中厚板的探伤质量.

Effect of the heating furnace time of casting slabs on the ultrasonic testing quality of medium plates

The relationships between the heating furnace time of casting slabs and the ultrasonic testing quality of hot-rolling medium plates were investigated. It is concluded that, (1) when the heating furnace time of 220 mm thickness casting slabs was less than 3 h, very bad ultrasonic testing quality of the plates would happen; (2) increasing the heating furnace time of the slabs could effectively improve the ultrasonic testing quality of the plates; (3) what caused the ultrasonic testing lost was micro-cracks in the pearlite band; (4) reducing the centerline segregation of the slabs could obviously improve the ultrasonic testing quality of the plates.