包套轧制法制备6.5%Si高硅钢及其性能特点

Preparation of 6.5%Si High Silicon Steel by Pack Rolling Method and its Performance Characteristics

本文针对6.5%Si高硅钢的室温脆性难以轧制问题,采用普通硅钢热轧板(≤3%Si)对高硅钢(6%~8%Si)钢坯进行包套,通过热轧、温轧及高温退火制备0.3 mm厚高硅钢带材。通过研究发现,包套高硅钢热轧板在室温和280℃温度区间发生了较为明显的脆性-韧性转变,在280℃拉伸时延伸率显著增大,断口形貌呈现出大量韧窝,表现为塑性断裂。根据实时监测的工艺参数可知,包套6.5%Si高硅钢热轧板在550~600℃温轧时的平均轧制力与板厚、辊缝、材料硬化程度及开轧温度等因素相关,压下率随着厚度的减薄先增大而后减小,减小的原因与轧制负荷趋于饱和及轧制厚度接近目标厚度有关。温轧成品板的包覆层与中间层之比为1/5,0.3 mm厚温轧板经高温退火后,制备出成品板磁性能优异,其高频铁损P0.2/10k为78.8 W/kg,明显低于普通的3%Si硅钢。

In view of the britleness and difficulty in rolling of 6.5%Si high silicon steel at room temperature,ordinary silicon steel hot rolled plate(≤3%Si)is used to cover the high silicon steel(6%-8%Si)billet,and produce 0.3 mm thick-ness high silicon steel strip by hot rolling,warm rolling and high temperature annealing.It is found that the hot-rolled high silicon steel by pack rolling has a brittle-ductile transition in the range of room temperature and 280°C,the elongation in-creases significantly at 280 C,and the fracture morphology exhibits a large number of toughness nests,manifested as plas tic fracture.According to the real-time monitoring of the process parameters,it can be seen that the average roling force of the pack-hotrolled 6.5%high silicon stl during wam olling at 550-600 Cisrelated otheplate thickness,roller ga material hardening degree,rolling temperature and other factors.The reduction rate first increases and then decreases with the thickness reduction.The reason for the reduction is related to the saturation of rolling load and the proximity of rolling thickness to the target thickness.The ratio of the cladding layer to the core layer of the warm-rolled-finished plate is 1/5.Warm rolled plate with a thickness of 0.3 mm was annealed at high temperature,and the high-frequency iron loss Pazoof fnished plate is78W/kg,presenting excelent magnetic properties,which is significantly lower than that of the ordinary silicon steel with 3%Si.