H-shaped Steel Flange Width via Split and Bend Rolling
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Solution Overview
Problem
Conventional methods for producing H-shaped steel with widened flanges are limited by the rate of flange spread during rough rolling, resulting in a maximum flange width of approximately 0.5 times the edging amount, and are constrained by equipment scale and reduction limits, making it difficult to achieve larger flange widths.
Innovation Solution
A method involving a rough rolling step with multiple calibers, where deep splits are created on the slab end surfaces using projections with acute-angle tip shapes, followed by sequential bending of the flange portions, allowing for increased flange widths beyond conventional limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If conventional rough rolling methods with splits and edging are used, then the manufacturing process is simple and equipment scale is limited, but the flange width is restricted to approximately 0.5 times the edging amount
Solution Approach 1:
The rough rolling process is divided into multiple distinct stages: split creation stage (forming initial splits on slab end surfaces), split deepening stage (widening and deepening splits in subsequent calibers), and flange shaping stage (sequential bending of flange portions). This segmentation allows each stage to be optimized independently, enabling flange widths exceeding conventional limits while maintaining process control
Solution Approach 2:
Splits are created and deepened in advance on the slab end surfaces before the final flange shaping operation. This preliminary action prepares the material structure to facilitate subsequent flange portion bending, enabling greater flange spread than conventional methods where splits are created and immediately bent without intermediate deepening
2Length of moving object
If the size of the slab material is increased to increase the edging amount, then the available edging amount increases, but the flange width is still not sufficiently widened due to device limits in equipment scale and amount of reduction
Solution Approach 1:
The process changes key parameters including split depth (made significantly deeper than conventional methods), split angle (optimized for material flow), and the number of sequential bending operations. These parameter changes enable achieving large flange widths from moderate-sized slabs by maximizing material utilization through controlled deformation rather than relying on large initial slab dimensions
3Length of moving object
If multiple calibers with sequential shaping are used, then the flange width can be increased beyond conventional limits, but the number of rolling passes and process time increases
Solution Approach 1:
The rough rolling process maintains continuous deformation of the material through multiple calibers without interruption. The split creation, deepening, and flange bending operations are performed in continuous sequence on the same material flow, minimizing idle time and ensuring that each caliber build upon the previous operation's results efficiently
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enables the production of H-shaped steel products with flange widths greater than conventional standards, achieving flange widths of up to 550 mm while maintaining a web height of 1650 mm, without the need for excessive slab size or equipment scale, thus overcoming the limitations of traditional techniques.
Implementation Method 1
projections to create splits vertically with respect to a width direction of the material to be rolled are formed. The projections formed in the first caliber and the second caliber have a tip angle of 40° or less.
Implementation Method 2
In a third caliber and subsequent calibers among the plurality of calibers, a step of sequentially bending divided parts formed by the splits is performed.
Data Source
AI summary
[Object] To produce an H-shaped steel product with a flange width larger than a conventional flange width by, in a rough rolling step using calibers in producing H-shaped steel, creating deep splits on end surfaces of a material (e.g., slab) using projections with acute-angle tip shapes, and sequentially bending flange portions formed by the splits.[Solution] Provided is a method for producing H-shaped steel using a slab as a material. In a rolling mill that performs a rough rolling step, a plurality of calibers to shape a material to be rolled, and a web thinning caliber to thin a web of the material to be rolled that has been shaped in the plurality of calibers are engraved, the number of the plurality of calibers being three or more. Shaping of a plurality of passes is performed on the material to be rolled in part or all of the plurality of calibers. In a first caliber and a second caliber among the plurality of calibers, projections to create splits vertically with respect to a width direction of the material to be rolled are formed. In a third caliber and subsequent calibers among the plurality of calibers, a step of sequentially bending divided parts formed by the splits is performed. The projections formed in the first caliber and the second caliber have a tip angle of 40° or less.