Numerical Simulations Of Temperature And Stress Fields In A Super-wide Slab Of Peritectic Steel Continous Casting Mold

In recent years, high efficient continuous casting technology has been looked as the primary tendency during the development of continuous casting, how to improve the quality and output of continous casting slab has been more interested. And the longitudinal crack rate of peritectic steel is much higher than other steel grades since wide slab was put into production at Wide Plate Plant.Two-dimentional (2-D) finite-element heat-transfer and stress models with moving coordinates were established to predict temperature and distribution of stress in a continous casting mold for steel slabs during operation. The effects of width of slab and operating conditions on distribution of stress on slab surface were analyzed in details, as summarized in the following.(1)At the mold exit, the distribution of the thickness of solidified shell was not even. In the wide face of slab, the thickness of solidified shell was more than 20mm near the center, and it was only 15mm near the corner.(2) The stress of the peritectic steel in the center place of slab was higher than non-peritectic steel.In the same conditions, the peritectic steel was much easier to form longitudinal crack than non-peritectic steel in the center place of slab.(3)In continous cast of peritectic steel slab, with the slab became wider, the stress on slab surface was increasd. In the center of the wide face, the incease was obvious; and the longitudinal crack was easier to form. The positions of the cracks were in the center of the wide face.(4) With the slab (3200mm×150mm) casting speed increased from 1.0m/min to 1.2m/min, the stress in the wide face center was decreased. And the amount of longitudinal crack in this area was decreased either. With the casting speed increased to 1.5m/min, the stress was inceased in the area which was 200mm from the center point of the wide face; the longitudinal crack was easier to form in this area. (5) With the slab (3200mm×150mm) superheat degree increased from 15℃to 25℃the extremum of the stress moved to the center of the wide face, and the possility of the longitudinal crack was was increased in this place.(6) With the slab cooling intensity increased, the surface stress was inceased. With the flow rate of cooling water changed from 6000L/min to 5500L/min, the slab surface stress was decreased. And the possility of the longitudinal crack was reduced. But the stress in the corner place was increased, and the shell thickness was getting thinner, the possibility of corner crack and steel breakout was increased.