镀锌/连退两用机组的退火周期与常规的连续退火机组明显不同,不仅退火周期较短、一次冷却速度低,而且无缓冷段。根据其工艺特点,以工业生产的热轧高温卷取低碳钢轧硬卷为试验材料,研究了退火温度和时间以及过时效对低碳钢和微碳钢组织和性能的影响。试验结果表明,不管是低碳钢还是微碳试验钢,退火后晶粒尺寸均较细,即使退火温度达到810℃,铁素体晶粒度仍在10.5级左右;经400℃×240 s过时效处理后,低碳钢的强度有所降低(10 MPa左右),延伸率有所提高,最高增加值为4.5%,微碳钢只有当退火温度达到810℃时,强度才有所降低(10 MPa左右),即过时效的作用不明显。通过采用微硼处理,优化连退和在线平整工艺,在热镀锌/连退两用机组上生产出了力学性能优良的产品。 The annealing cycle of the galvanized / double-alye unit is obviously different from that of the conventional continuous annealing unit. The annealing period is short, the primary cooling speed is low, and there is no slow cooling section. According to the characteristics of the process, the low carbon steel roll was taken as the test material by the high temperature hot rolling of industrial production. The effect of annealing temperature and time and over aging on microstructure and properties of low carbon steel and micro carbon steel was studied. The experimental results show that the grain size of the annealed steel is fine even in the low carbon steel or the micro-carbon test steel. The ferrite grain size is still about 10.5 even after the annealing temperature reaches 810 ℃. After 400 ℃ × 240 s After aging treatment, the strength of mild steel is reduced (about 10 MPa), the elongation is increased, and the maximum added value is 4.5%. The strength of mild steel only decreases when the annealing temperature reaches 810 ℃ (10 MPa or so), that is, the role of over-aging is not obvious. Through the use of micro-boron treatment, optimization of the back-line and on-line formation process, the hot galvanized / back and forth dual-use unit produced a good mechanical properties of the product.