同钢种复合钢板“中线”缺陷成因的研究分析

Causes Analysis on Centreline Defect of Clad Steel Plate with Same Steel Grade

舞钢通过轧制复合法实现了200 mm以上厚度同钢种复合钢板的规模化生产,但试制阶段前期在切边后探伤合格钢板复合层发现"中线"缺陷。研究分析结果表明:复合层存在一条宽度和厚度约0.1 mm的富氧颗粒区,主要由Si、Fe的氧化物组成。这些类似夹杂物的氧化物在轧制过程中发生变形,成为裂纹源,导致复合层开裂,贯穿整个复合层形成"中线"缺陷,降低了复合板的结合率,致使钢板不能交付使用。

Wugang achieves the commercialized production of clad steel plate with same steel grade over 200 mm thickness in accordance with Chinese GB standard by roll cladding method. But centreline defect is discovered at the bonding interface of qualified ultrasonic detected steel plate after trimming. The analysis results show that there existed 0. 1 mm wide and thick zone of oxygen enriched parcles at the bonding interface mainly consisting of Si and Fe Oxides. These inclusion - like oxides were deformed during rolling, resulting in centreline defect in the form of bonding interface crack as origin through the entire interface. The defect reduced the bonding rate of clad plate and caused the finish plate undeliverable for any application.