船用5083-H321铝合金板生产工艺研究

Study on the production process of 5083-H321 aluminum alloy plate for ship

分析了5083铝合金半连续铸造的铸锭经双级均匀化处理后的组织变化,研究了热轧、冷轧、退火工艺参数对5083-H321铝合金板力学性能、微观组织及耐腐蚀性的影响。结果表明:为满足力学性能要求,热轧和冷轧分别保留了纤维状组织;热轧纤维状变形组织易引起剥落腐蚀倾向,冷轧小压下量条件下压延组织提高了晶界活性,易发生晶间腐蚀;接近250℃的高温回复退火作为脱敏处理方法,在不大幅降低轧制后合金性能的同时可提高合金的耐腐蚀性。6 mm厚的5083-H321铝合金板材生产工艺:260℃热轧终轧温度生产的热轧卷250℃进行脱敏处理;3 mm厚的5083-H321铝合金板材生产工艺:330℃终轧温度生产的5 mm厚热轧卷,经40%加工率冷轧到成品厚度,250℃再进行脱敏处理。

The microstructure of 5083 aluminum alloy semi-continuous casting ingot after two-stage homogenization was analyzed. The effects of hot rolling, cold rolling and annealing process parameters on the mechanical properties, the microstructure and corrosion resistance of 5083-H321 aluminum plate were studied. The results show that in order to meet the requirements of mechanical properties, fibrous microstructure has been retained in hot rolling and cold rolling, respectively. Hot-rolled fibrous microstructure tends to cause exfoliation corrosion. Cold rolling with small reduction increases grain boundary activity and the opportunity of intergranular corrosion. As a desensitization treatment method, high temperature recovery annealing near 250 ℃ can improve the corrosion resistance of materials without significantly reducing the mechanical properties after rolling. The production process of 6 mm-thick 5083-H321 is final hot rolling at 260 ℃ and desensitization at 250 ℃. The production process of 3 mm-thick 5083-H321 is final hot rolling at 330 ℃ to 5 mm-thick coil, cold rolling with 40% reduction to 3 mm plate, and desensitization at 250 ℃.