A nalysis and C ontrol of S urface D efects in Q 690D S lab for H eavy P late in B aotou S teel
WANG Hao
QIE Junmao
DONG Fang
Abstract：The surface defects such as oscillation marks and corner cracks appeared in the Q690D slab for heavy plate in Baotou Steel. In order to solve the problems, the influences of the performance of mould powder, oscillation parameters of the crystallizer, cooling effect of continuous caster and the content of nitrogen in the steel on the surface defects were analyzed. By decreasing the viscosity and increasing the basicity of mould powder, enhancing the oscillation frequency and reducing the amplitude of the crystallizer, controlling the range of straightening temperature between 900 and 1 300℃(the plastic zone)and controlling the content of nitrogen in the steel≤50×10-6, the oscillation marks were lightened efficiently, the corner crack and star crack were removed and the Q690D slab quality was improved.
Keywords：Q690D continuously cast slabsurface defectoscillation markcorner crackstar crack
Publication Date：2014-01-01
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：4( 34-36,39 )