Control method for corner cracks of boron-containing steel plate slabs

A corner crack and control method technology, applied in the field of metallurgy, can solve the problems of poor control effect of boron-containing steel slab corner crack defect, unsatisfactory control of boron nitride precipitation behavior, increase smelting cost, etc., so as to reduce crack defects , The effect of improving the metal yield and improving the quality of the casting billet

Active Publication Date: 2017-06-13
INST OF RES OF IRON & STEEL JIANGSU PROVINCE
View PDF8 Cites 14 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, in the production of boron-containing steel slabs, the method of controlling the N content of molten steel and adding titanium to reduce the transverse cracks at the corner of the slab is widely adopted, but the N content needs to be strengthened from the whole process of steelmaking-refining-continuous casting, which is affected by alloying elements and process flow It is difficult to control stab

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] The chemical composition of boron-containing steel includes: C 0.18%, Si 0.19%, Mn 0.54%, P0.019%, S 0.012%, Al 0.03%, B 0.0018%, N 0.0045%, and the balance is iron and unavoidable impurities. The production process of boron-containing steel slabs includes molten iron pretreatment, converter smelting, out-of-furnace refining, and slab continuous casting; a total of 18 furnaces of steel are produced in one tundish, and the cross-sectional size of the slab is: 1228×220mm 2 , the casting speed is 1.3m / min, the water volume on one side wide surface of the crystallizer is 2984L / min, and the water volume on one side narrow surface of the crystallizer is 528L / min, of which Crystallizer water quantity Q 1 Quantity of water in wide surface Q 1-w Q 1-h Satisfaction: (Q 1-w / w) / (Q 1-h / h) = 1.01. The secondary cooling adopts the full coverage spraying method, and the total water volume of the secondary cooling is 1756L / min, of which The proportions of cooling water in eac...

Embodiment 2

[0021] The chemical composition of boron-containing steel includes: C 0.17%, Si 0.20%, Mn 0.43%, P0.012%, S 0.016%, Al 0.045%, B 0.0013%, N 0.0045%, and the balance is iron and unavoidable impurities. The production process of boron-containing steel slabs includes molten iron pretreatment, converter smelting, out-of-furnace refining, and slab continuous casting; a total of 15 furnaces of steel are produced in one tundish, and the cross-sectional size of the slab is: 1510×220mm 2 , the casting speed is 1.15m / min, the water volume on one side wide surface of the crystallizer is 5043L / min, and the water volume on one side narrow surface of the crystallizer is 497L / min, of which Crystallizer water quantity Q 1 Quantity of water in wide surface Q 1-w Q 1-h Satisfaction: (Q 1-w / w) / (Q 1-h / h) = 1.48. The secondary cooling adopts the full coverage spraying method, and the total water volume of the secondary cooling is 2865L / min, of which The proportions of cooling water in e...

Embodiment 3

[0023] The chemical composition of boron-containing steel includes: C 0.18%, Si 0.25%, Mn 0.40%, P0.017%, S 0.009%, Al0.05%, B 0.0015%, N 0.0051%, and the balance is iron and unavoidable impurities. The production process of boron-containing steel slabs includes molten iron pretreatment, converter smelting, out-of-furnace refining, and slab continuous casting; a total of 25 furnaces of steel are produced in one tundish, and the cross-sectional size of the slab is: 1383×220mm 2 , the casting speed is 1.25m / min, the water volume on one side wide surface of the crystallizer is 3763L / min, and the water volume on one side narrow surface of the crystallizer is 575L / min, of which Crystallizer water quantity Q 1 Quantity of water in wide surface Q 1-w Q 1-h Satisfaction: (Q 1-w / w) / (Q 1-h / h) = 1.04. The secondary cooling adopts the full coverage spraying method, and the total water volume of the secondary cooling is 2662L / min, of which The proportions of cooling water in eac...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention belongs to the technical field of metallurgy, and particularly relates to a control method for corner cracks of boron-containing steel plate slabs. The production procedure of a boron-containing steel plate sequentially comprises molten iron pre-treatment, converter smelting, secondary refining and plate slab continuous casting. In the continuous casting process, the ratio of the water amount of a crystallizer to the product of the casting blank section size and the pulling speed is controlled to be 0.02-0.03; meanwhile, the ratio of the wide face water amount/wide face size of the crystallizer to the narrow face water amount/narrow face size is controlled to be 1-1.5; a full-width coverage spraying manner is adopted as a secondary cooling manner, and the ratio of the total water amount of secondary cooling to the product of the casting blank section size and the pulling speed is controlled to be smaller than or equal to 0.0075; and according to the proportion of the water amount of each segment in the total water amount, the foot roller area accounts for 10%-15%, the zero segment area accounts for 35%-45%, the arc-shaped segment area accounts for 25%-35%, and the straightening area accounts for 5%-10%. According to the control method for the corner cracks of the boron-containing steel plate slabs, the straightening temperature rises, the corner cross cracks are eliminated, and the hot-rolled coiled plate edge portion surface warping defect occurrence rate caused by the corner cross cracks of the plate slabs is reduced to 0.2% or below from 3%.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, in particular to a control method for corner cracks of boron-containing steel slabs. Background technique [0002] A small amount of boron (5×10 -6 ~50×10 -6 ) can significantly improve the hardenability of steel, obtain excellent mechanical properties such as high strength, high toughness, and high hardness after heat treatment, and save a lot of precious and rare metal elements. However, since the trace element boron is added to the steel, the crack sensitivity of the steel is increased, and it is easy to cause transverse cracks at the corners of the continuous casting billet, which in turn causes warped skin defects at the edge of the hot-rolled coil, resulting in the degradation of the coil or the direct rejection of the coil . [0003] Most of the cracks at the corners of the continuous casting slab start from the mold, where the positive segregation area at the bottom of the vibration...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): B22D11/22C22C38/32C22C38/02C22C38/04C22C38/06
CPCB22D11/22B22D11/225C22C38/004C22C38/02C22C38/04C22C38/06C22C38/32
Inventor 邹长东苏笃星周青峰麻晗
Owner INST OF RES OF IRON & STEEL JIANGSU PROVINCE
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products