摘要
目的研究破鳞工艺对热轧带钢表面氧化铁皮开裂剥离及酸洗速率的影响。方法采用自主设计的拉伸矫直试验机对热轧带钢进行破鳞试验,通过调节拉矫机的压下量和张紧力,获取不同拉矫参数下的破鳞试样。利用金相显微镜对不同拉矫参数下的带钢试样的表面和界面形貌进行观察,分析氧化皮的剥落率和破裂情况,比较张紧力和压应力的破鳞作用。采用电位导数首零法对试样进行酸洗速率测定,研究拉矫工艺参数对酸洗速率的影响。结果氧化皮剥落率随着压下量和张紧力的增大而增大,压下量对氧化皮的剥离作用有较强影响。保持压下量或张紧力不变时,酸洗时间随着延伸率的增大而减小;延伸率相近时,较大的压下量对应延伸率的酸洗时间更短;延伸率达到1.36%左右时,酸洗时间达到饱和最低点值24.3 s不再变化。结论氧化皮在受压应力作用时主要以剥落为主,酸洗时间迅速减少;受张紧力作用时主要以产生裂纹为主,对酸洗速率的提升作用弱于压下量。拉矫时采用提高压下量的方法更利于提高酸洗速率。
Objective To study the effect of descaling parameters on oxide scale spalled and its pickling speed. Methods The hot-rolled strip was descaled by the self-designed descaling and tension leveler by adjusting the screw down amount and the tension, the test samples with different process parameters were analyzed and the surface and the interface morphology of samples were observed by metalloscope to analyze the shell-off ratio and the cracking of the oxide scales and compare the scale breading effects by tension and by compressive stress. And the method of first zero potential differential value was used to determine the pickling rate to explore the influence of stretch rolling parameters on pickling rate. Results The spalling rate of oxide scale increased with the in- crease of the amount of screw down and tension, but the former parameter reflected a stronger effect. When the screw down amount and the tension remained, the pickling time decreased with the increase of elongation. When the value of elongation was similar,the bigger screw down amount led to less pickling time. When elongation reached about 1. 36% , the pickling time was maintained at the lowest saturation valued around 24.3 s. Conclusion In conclusion, oxide scale mainly spalled under compressive stress and the pickling time decreased rapidly. Cracking mainly occurred under tension and the effect of tension on increase of pickling rate was weaker than that of compressive stress. It was more beneficial to improve the pickling rate by improving the screw down amount.
出处
《表面技术》
EI
CAS
CSCD
北大核心
2015年第7期125-130,共6页
Surface Technology
基金
国家自然科学基金(51105143
51375164)~~
关键词
拉矫
氧化皮
酸洗
压下量
张紧力
descaling
oxide scale
pickling
screw down amount
tension
