降低Q235热轧钢板带状组织的工艺参数优化

Optimization on process parameters for reducing banded structure of Q235 hot rolled steel plate

为降低Q235热轧钢板的带状组织、提升其弯曲成形性,利用Taguchi正交试验法选定了精轧轧制速度、精轧完成温度、盘卷速度及盘卷温度这4项工艺参数,探讨了Q235热轧钢板热轧后上述工艺参数对带状组织最大厚度与最大长度的影响,确定了Q235热轧钢板的最佳热轧工艺参数组合,并进行了弯曲试验验证。结果显示:各工艺参数对带状组织最大厚度的影响程度顺序为精轧完成温度>精轧轧制速度>盘卷温度>盘卷速度;而对带状组织最大长度的影响程度顺序为精轧完成温度>盘卷温度>盘卷速度>精轧轧制速度;降低Q235热轧钢板中带状组织的最佳工艺参数组合为精轧轧制速度为0.80 m·s^(-1)、精轧完成温度为870℃、盘卷速度为2.80 m·s^(-1)、盘卷温度为650℃,在此热轧条件下带状组织的最大厚度减少了65%、最大长度减少了74%。

To reduce banded structure in Q235 hot rolled steel plate and improve its bending formability, four process parameters such as finishing rolling speed, finishing rolling temperature, coiling speed and coiling temperature were selected by Taguchi orthogonal experiment method, and the influences of process parameters on maximum thickness and maximum length of banded structure were discussed after Q235 steel plate was hot rolled. Then, the best hot rolling process parameters combination for Q235 hot rolled steel plate was confirmed, and the bending test was carried out. The results show that the influence degree of process parameters on the maximum thickness of banded structure is in the order of finishing rolling temperature > finishing rolling speed > coiling temperature > coiling speed, and the influence degree on the maximum length of banded structure is in the order of finishing rolling temperature > coiling temperature coiling speed> finishing rolling speed. The optimal combination of hot rolling process parameters to reduce the banded structure of Q235 hot rolled steel plate is the finishing rolling speed of 0.8 m·s^(-1), the finishing rolling temperature of 870 ℃,the colling speed of 2.8 m·s^(-1),and the colling temperature of 650 ℃. Under this hot rolling condition, the maximum thickness of banded structure is reduced by 64%, and the maximum length is reduced by 74%.