Evolution behavior of transverse cracks on Q345 slab surface during hot rolling process
In the continuous casting production process,due to influence of chemical elements,temperature,me-chanical stress and other factors,the casting billet will inevitably produce surface transverse cracks.During the roll-ing process,surface transverse cracks of the casting billet will further amplify,which affects the surface quality of the subsequent rolled products,and even cause the product to be scrapped.Therefore,the evolution behavior of Q345 steel surface transverse crack in hot rolling process was studied,and the laboratory hot rolling experiment was carried out on the prefabricated"V"crack on the billet surface.The corresponding rolling model was established,and the correctness of the model was verified by the experiment.The on-site slab rolling process was used to estab-lish the transverse crack rolling model with different widths(1,2,3 mm)on the Q345 steel surface,and evolution characteristics of cracks with different widths in hot rolling process were analyzed.The results show that the surface bonding phenomenon occurs during the rolling process of cracks with width of 1 mm,while the two sides of cracks with width of 2 mm and 3 mm gradually unfold and finally expose to the surface of the rolled material.By analyzing the change of crack size and aspect ratio,it can be found that the unfolding width of crack with different widths in the rolling process increases linearly,and the unfolding width of 1,2 and 3 mm width cracks reaches 30,32 and 34 mm after rolling,respectively,while the crack depth decreases obviously in the early stage of rolling,and decreases little in the next few passes.The change trend of aspect ratio of crack with different widths is the same as the change trend of crack depth,the initial change is large,and crack aspect ratio in the next passes tends to be 0.The research results can provide a theoretical reference for optimizing the rolling production process.
Q345 slabsurface transverse crackevolution behaviorfinite element simulationhot rolling
NETL
NSTL
万方数据
维普
