In order to enhance the quality of 20 # carbon-steel on the continuous casting production line,formation mecha-nism of pinholes
and non-metallic inclusions in billets and numerical simula tion of
flow field about molten steel in tundish by a mathematic model is st udied and analyzed.It is shown that the structure and operation of tundish p lay an important part for quality assurance of the20 # carbon-steel's products.So some studies about the structure and operatio n of tundish have been carried as follow:(1)optimizing the tundish construc tion,to enhance the height of molten steel in tundish,and lengthen the resi dence time of molten steel,which is useful for full blend and diffusion of pinholes and non-metallic in-clusions in billets and for homogenization of molten steel;(2)improving the influent and effluent operation of liquid steel,to avoid the contact of liquid steel with air,decrease re-
oxidation ;(3)the casting temperature has been controlled more closely,to decrease th e non-metallic inclusion content in billets because of the re-oxidation of steel and to reduce the erosion of tundish Lining.After above measures being taken,the quality of 20 # carbon-steel and the service life of equip-ment had been improved remar kably.