Research on the Characteristics and Formation Mechanism of Warpage Defects in Hot-rolled Q235B Steel
The warping defect is one of the typical surface defects of hot-rolled Q235B steel strip,which has the characteristics of irregular distribution and shallow depth,and seriously affects the surface quality of hot-rolled steel strip products.In this paper,the causes of warping defects in hot-rolled Q235B steel strip were analyzed by using a combination of metallographic microscope,scanning electron microscope,and energy spectrometer,and improvement measures were proposed.The results showed that the main causes of warping defects were the formation of cracks on the surface of the steel billet,the failure to remove the iron oxide scale completely at the cracks,the introduction of secondary oxides of Si and Mn and iron oxide scale into the steel plate surface during subsequent rolling processes,and the entry of some slag from the crystallizer into the surface of the cast billet,resulting in warping defects.By adopting protective casting,optimizing the insertion depth of submerged nozzle,stabilizing the casting speed,and controlling the surface cleanliness during high-pressure descaling during rolling process,the incidence of warping defects can be effectively reduced.
NETL
NSTL
万方数据
