张瑜, 漆鑫, 张红斌. Analysis on Forming Cause of Surface Longitudinal Crack of Steel Q235B Hot-Rolled Plate and Controlling Process[J]. Special Steel, 2016, 37(1): 29-33.
张瑜, 漆鑫, 张红斌. Analysis on Forming Cause of Surface Longitudinal Crack of Steel Q235B Hot-Rolled Plate and Controlling Process[J]. Special Steel, 2016, 37(1): 29-33.DOI:
The flowsheet for 10 ~20 mm hot-rolled plate of Q235B steel (0. 11% ~0. 17% C) is hot metal pretreatment-50 t converter-argon blowing-(200 ~230)mm x (900 ~ 1 600) mm slab casting-hot rolling process. The analysis results show that the surface crack of hot-rolled plate stems from casting slab longitudinal cracks of steel Q235B. The effect of composition
liquid overheat extent
casting speed
casting secondary water rate and mold powder on longitudinal crack of casting slab has been statistically analyzed. With the measures including controlling Mn/S ≥40
liquid overheat extent 15 ~35 °C
casting speed 1. 15 m/min
adjusting secondary water rate according to season and using mold powder with melting point ≥1 100°C
viscosity 0. 20 ~ 0. 32 Pa .s and basicity ≥1. 10
the ratio of occurrence of steel Q235B hot- rolled plate surface longitudinal crack decreases to ≤0. 96% from original 3. 51% .