CN-119973069-B - Method for reducing transverse crack of outer arc angle of casting blank of Danieli casting machine

Abstract

The invention belongs to the technical field of steel smelting, and particularly relates to a method for reducing transverse cracks of an outer arc angle of a casting blank of a Danieli casting machine. The method comprises the following steps of (1) changing a bolt fixing mode of a trunnion under a bending section from full tightening to half tightening, enabling a gap to exist between the bolt and the trunnion, and additionally installing a gasket in the gap, (2) grinding the trunnion abrasion burrs and the like cleanly during offline preparation, adjusting the elevation of a preparation table according to the size of the trunnion after grinding, guaranteeing offline preparation precision, (3) translating the whole bending section to the outer arc side by 0.5mm in a cold state, (4) adjusting the gap between the trunnion under the bending section and a baffle to be within 0.2mm, and (5) adjusting a secondary cooling process after a crystallizer according to whether a transverse crack defect of an outer arc angle of a casting blank penetrates through the corner. The invention aims at the design defects of the darniy casting machine to improve the structure and the process, thereby reducing the defects of transverse crack of the outer arc angle of the casting blank and the like.

Inventors

• ZHANG BO
• ZHOU QINGFEI
• SUN YULEI
• CHEN CHUANLEI
• WANG XUEXIN
• CAO YUNTAO
• ZHAO MIN
• ZHAO DENGBAO
• CHEN CHANGYI
• LI CHENGLONG
• CHEN YAO
• LI NING

Assignees

• 山东钢铁集团日照有限公司

Dates

Publication Date

20260512

Application Date

20250403

Claims (2)

1. 1. A method for reducing transverse cracks of an outer arc angle of a casting blank of a darniley casting machine, which is characterized by comprising the following steps: (1) The bolt fixing mode of the trunnion under the bending section is changed from full tightening to half tightening, so that a gap exists between the bolt and the trunnion, and a gasket is additionally arranged in the gap; (2) During offline preparation, the trunnion abrasion burrs are polished cleanly, and the elevation of the preparation table is adjusted according to the polished trunnion size, so that offline preparation precision is ensured; (3) In a cold state, translating the whole curved section to the outer arc side by 0.5mm; (4) The gap between the trunnion and the baffle plate under the bending section is adjusted to be within 0.2 mm; (5) And adjusting a secondary cooling process after the casting blank is discharged out of the crystallizer according to whether the transverse crack defect of the outer arc angle of the casting blank penetrates through the angle.
2. 2. The method for reducing the transverse crack of the outer arc angle of a casting blank of a darby casting machine according to claim 1, wherein the adjustment method of the secondary cooling process in the step (5) is that if the non-corner penetrating defect occurs, the secondary cooling water quantity is increased by 10% -15%.

Description

Method for reducing transverse crack of outer arc angle of casting blank of Danieli casting machine Technical Field The invention belongs to the technical field of steel smelting, and particularly relates to a method for reducing transverse cracks of an outer arc angle of a casting blank of a Danieli casting machine. Background The darnili casting machine has the defects that the arc radius of the continuous casting machine is small, the bending section is forced to displace in the production process due to the fixing mode of the bending section, the outer arc of the casting blank is easy to generate angle transverse crack and the like due to the design and other reasons; The transverse crack of the outer arc angle of the casting blank causes the peak crack of the steel plate to be changed and judged, thereby seriously affecting the cost and quality, and then frequently causing the steel making to carry out the production supplement, and seriously affecting the order delivery and the reputation of the company. Disclosure of Invention The invention aims to provide a method for reducing transverse crack of an outer arc angle of a casting blank of a Danieli casting machine, so as to solve the problems in the prior art. The technical scheme adopted for solving the technical problems is as follows: a method for reducing transverse cracking of an outer arc angle of a casting blank of a Darling casting machine comprises the following steps: (1) The bolt fixing mode of the trunnion under the bending section is changed from full tightening to half tightening, so that a gap exists between the bolt and the trunnion, and a gasket is additionally arranged in the gap; (2) During offline preparation, grinding trunnion abrasion burrs and the like cleanly, and adjusting the elevation of the preparation table according to the size of the ground trunnion so as to ensure the offline preparation precision; (3) In a cold state, translating the whole curved section to the outer arc side by 0.5mm; (4) The gap between the trunnion and the baffle plate under the bending section is adjusted to be within 0.2 mm; (5) And adjusting a secondary cooling process after the casting blank is discharged out of the crystallizer according to whether the transverse crack defect of the outer arc angle of the casting blank penetrates through the angle. Furthermore, the adjustment method of the secondary cooling process in the step (5) is that if the defect of non-corner penetration is generated, the secondary cooling water quantity is increased by 10-15%. The invention has the following beneficial effects: 1. The invention aims at the design defects of the darniy casting machine to improve the structure and the process, thereby reducing the defects of transverse crack of the outer arc angle of the casting blank and the like. 2. When the casting machine runs at high temperature, the bending section is expanded by heating and can deviate to the inner arc side, and the cold state pre-displacement by 0.5mm can offset about 80% of the thermal displacement, so that the actual position of the bending section in the hot state is close to the theoretical design center line. 3. The gap between the lower trunnion and the baffle plate is 0.2mm to restrict macroscopic displacement, the gasket absorbs microscopic stress, hierarchical control is formed, and cooling uniformity of the corner of the casting blank is improved. 4. The defect of non-corner penetration is generated, the secondary cooling water quantity is increased by 10% -15%, the cooling temperature of the casting blank rapidly exceeds the first brittle transition temperature, and the transverse crack defect of the outer arc angle of the casting blank is reduced. Drawings FIG. 1 is a schematic view of the bolting means of the trunnion under the bending part of the present invention. Wherein, 1, lower trunnion, 2, gasket, 3.U, seat and 4, bolt. Detailed Description The present invention will be described in further detail with reference to specific embodiments in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention. A method for reducing transverse cracking of an outer arc angle of a casting blank of a Darling casting machine comprises the following steps: (1) The bolt 4 fixing mode of the lower trunnion 1 of the bending section is changed from full tightening to half tightening, so that a gap exists between the bolt 4 and the lower trunnion 1, and a certain stress releasing space is provided for the bending section. And the gasket 2 is additionally arranged in the gap, and the gasket 2 with the thickness of 0.05-0.1mm is generally additionally arranged, and the specific requirement is determined according to the actual working condition. The gap between the bolt 4 and the lower trunnion 1 c