两次冷轧压下率分配对IF钢深冲性能的影响

为提高IF钢深冲性能,以热轧带钢为原料,采用两次冷轧的实验方法,在实验室冷轧机上进行润滑轧制·冷轧实验表明,在总压下率一定的情况下,两次冷轧压下率的分配是影响IF钢深冲性能的关键·实测轧制试件的r值,得出在总压下率一定时,两次冷轧比一次冷轧的塑性应变比r值要高;同时得出一次冷轧压下率较小,二次冷轧压下率较大时,可使r值提高;如果冷轧总压下率适当提高,也可使r值提高;两次冷轧压下率均为75%时,r值可达3 2以上·通过对轧制试样的ODF织构分析,表明与实测r值一致·对显微组织观察表明,晶粒呈等轴状时有利于深冲性能·

Effect of Reduction Partition in Two-Pass Cold Rolling on Drawability of IF Sheet

A 2-pass cold rolling process was conducted in lab with lubricant used for hot rolled IF strips, with the purpose of improving the drawability of IF steel after cold rolling. The results show that the partition of the fixed overall reduction is of key importance to the drawability of the IF sheet. If the overall reduction remains unchanged, the measured plastic strain ratio, r, after 2-pass rolling is higher than that after single pass rolling. The r increases if the 1st pass reduction is smaller than the 2nd one, and the r also increases if the overall reduction increases properly. The r can be up to over 3.2 if both the reduction ratios are 75%. The ODF texture analysis made to the rolled specimen showed its identity with the r measured, and the micrographic results show that the equiaxed grain benefits the drawability.