No-slit Hot Rolling of Railroad Rails for Uniform Billets
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Solution Overview
Problem
Existing methods for recycling worn railroad rails fail to produce a one-piece billet or slab due to issues like laps, seams, and folds, and when rails are slit into pieces, variations in the head portion size and shape complicate processing, making it difficult to achieve identical final end piece sizes.
Innovation Solution
A 'no-slit' method involving heating the rail to a plastic state, followed by a series of reduction passes without initial slitting, then slitting into two pieces, and further processing through reduction passes to achieve uniform cross-sections and identical shapes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the rail is slit into separate pieces before reshaping, then the processing can be simplified, but the variations in head portion size and shape make it difficult to achieve identical final end piece sizes
Solution Approach 1:
The rail is heated to a plastic state before any shaping operations, which softens the material and allows for more uniform deformation during subsequent rolling passes, reducing the impact of initial head portion variations
Solution Approach 2:
The invention changes the physical state of the rail material from solid to plastic through heating, which fundamentally alters how the material responds to deformation forces, enabling better size uniformity in the final products
2Manufacturing precision
If the rail is not slit and processed as one piece, then size variations are maintained, but producing a one-piece billet or slab is difficult due to laps, seams and folds
Solution Approach 1:
The invention divides the processing into distinct stages: first processing the entire rail as one piece through multiple rolling passes to eliminate defects, then slitting into final pieces, ensuring both quality and manufacturability
Solution Approach 2:
Multiple preliminary rolling passes are performed on the unslit rail to pre-shape it and eliminate potential defects before the final slitting operation, ensuring high product quality
3Manufacturing precision
If multiple guiding systems are used to process different head portion sizes, then identical final end piece sizes can be achieved, but the complexity and cost of processing increases
Solution Approach 1:
A single guiding system is designed to handle all rail variations by processing the entire rail as one piece through standardized rolling passes, eliminating the need for multiple specialized guiding systems while maintaining product uniformity
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 allows for the production of uniform bar pieces with reduced variations, improving the quality of recycled products and reducing the complexity and cost of processing by minimizing the need for multiple guiding systems.
Implementation Method 1
heating the material of the rail to a plastic state
Data Source
AI summary
A method of recycling a one-piece rail having a base portion and a head portion spaced from each other by a substantially flat web portion. The steps include: heating the rail to a plastic state; feeding the heated rail through a first reduction pass to reduce a cross section of the rail without slitting the rail; feeding the bar through a second reduction pass in which the cross section of the bar is further modified; feeding the bar through a third reduction pass in which the cross section of the bar is further modified and then slitting the bar along the web portion into two bar pieces, one containing the former head portion and one containing the former base portion, as the bar leaves the third reduction pass; and rolling the two bar pieces through a series of reduction passes to produce a desired final cross section of the pieces.