Round ingot die and round ingot manufacturing method

Abstract

The invention relates to the technical field of casting of ingots, and provides a round ingot die. The round ingot die comprises a die body, a lug and an insulation board; an inner cavity is formed in the die body; the cross section of the outer side surface of the die body is polygonal wave shaped. According to the round ingot die, the radiating area of the side surface of the ingot is increased; hot melt at the outermost layer can be quickly cooled to form a chilling layer; the thickness increase of the chilling layer is sped up; therefore, static pressure in pouring of hot melt can be borne; crack can be prevented; the difficulty at pouring of the round ingot can be greatly reduced; meanwhile, the size precision of the outer side surface of the round ingot die cannot influence the size precision of the round ingot, so that the requirement on the processing precision of the outer side surface of the round ingot die is reduced, the process and working houses are decreased, and the cost can be saved. The invention further provides a round ingot manufacturing method. The method is that the degree of superheat of hot melt is 40 to 55 DEG C; the linear speed of pouring of an ingot body is 80 to 220mm / min; the linear speed of filling and pouring of a dead head of the insulation board is 35 to 90mm / min. The method can properly reduce the casting temperature and speed; the round ingot can be quickly radiated; therefore, the surface cracks can be decreased.

Description

technical field [0001] The invention relates to the technical field of steel ingot casting, in particular to a round steel ingot mold and a method for manufacturing the round steel ingot. Background technique [0002] The existing steel ingots that are directly used for rolling seamless steel pipes, in order to speed up the heat dissipation during casting and ensure the manufacturing and service performance of the steel ingots, the cross-section is set as a circular wavy polygon with 19 to 27 sides of waves. The steel ingot mold of this kind of circular wave polygonal steel ingot, the dimensional accuracy of its die cavity directly affects the precision and the quality of circular wave polygonal steel ingot surface, therefore, very high to the dimensional accuracy requirement of circular wave polygonal model cavity, the production and processing difficulty of steel ingot mold is big, The process is complicated, and it is difficult to install the cap opening insulation board....

AI Technical Summary

Problems solved by technology

[0002] The existing steel ingots that are directly used for rolling seamless steel pipes, in order to speed up the heat dissipation during casting and ensure the manufacturing and service performance of the steel ingots, the cross-section is set as a circular wavy polygon with 19 to 27 sides of waves. The steel ingot mold of this kind of circular wave polygonal steel ingot, the dimensional accuracy of its die cavity directly affects the precision and the quality of circular wave polygonal steel ingot surface, therefore, very high to the dimensional accuracy requirement of circular wave polygonal model cavity, the production and processing difficulty of steel ingot mold is big, The process is complicated, and it is difficult to install the cap opening insulation board

[0003] However, the conventional round steel ingot production method is very prone to longitudinal cracks due to the small heat dissipation area of ​​the steel ingot mold and the coordination between pouring temperature and pouring speed, resulting in high scrap rate of steel ingots and low qualified rate, so it cannot be mass-produced

The invention patent CN101195153A published on June 1, 2008 provides a casting mold and casting method for producing round steel ingots; with this invention, because steel ingots are prone to surface cracks, mass production is not formed

The invention patent CN 101524745A published on September 9, 2009 discloses a casting mold and casting method for producing round steel ingots. Moderate injection speed is not easy to coordinate. It can only be used for small batch production in a small melting furnace where only one steel ingot is poured in one ladle of molten steel. The above rising holes can only be used for pouring large steel ingots. For small and medium steel ingots of 2 to 7 tons commonly used for rolling seamless steel pipes, because the rising holes are too close to the wall of the ingot mold, the solidification shell during the solidification process of the steel ingot will be washed away greatly. The solidified shell is not uniform, and it is easy to form cracks on the surface of the steel ingot

The large tonnage round steel ingot mold CN200720030414.4 disclosed on October 8, 2007 has an inner cavity taper of 2.22 to 2.70%. In this invention, the taper is too large and the inner cavity of the ingot mold has a reverse taper, so the metal yield is low. It is only suitable for the production of forged ingots, not for the casting of steel ingots for direct rolling seamless steel pipes

The generation of surface cracks is directly related to the heat dissipation speed, pouring temperature and speed of the round steel ingot mould. Although the above two round steel ingot molds and steel ingot manufacturing methods have low processing difficulty, the heat dissipation effect is limited, and neither can effectively prevent the generation of surface cracks.

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