Railway Brake Disc Ring Rolling Grain Alignment
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Solution Overview
Problem
High-speed railroad vehicles require brake discs with enhanced physical properties to prevent linear radial cracks and extend service life, as existing brake discs suffer from surface defects and reduced lifespan due to frequent braking operations.
Innovation Solution
A manufacturing method involving ring rolling, followed by heat treatments and mechanical processes, to align crystal grains in the disc's rotating direction, enhancing resistance to brake pad contact and preventing surface cracks, using SFCMV1 steel with specific composition and processing steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If conventional manufacturing methods are used for brake discs, then production is simpler and faster, but linear radial cracks develop on the disc surface reducing service life
Solution Approach 1:
The patent applies ring rolling process parameters to change the crystal grain structure of the brake disc, transforming the material parameters to achieve crack resistance while maintaining manufacturing feasibility through controlled processing conditions
Solution Approach 2:
The patent replaces conventional mechanical manufacturing methods with ring rolling technology, substituting a mechanical process that inherently produces beneficial grain alignment and structural properties that prevent crack formation
2Reliability
If brake disc undergoes frequent braking operations, then braking function is maintained, but surface defects and cracks increase reducing durability
Solution Approach 1:
The patent applies ring rolling processing in advance during manufacturing to pre-align crystal grains and create a surface structure resistant to cracking, performing the protective action before the brake disc enters service and undergoes braking operations
Solution Approach 2:
The ring rolling process creates a compressed and aligned surface layer that acts as a cushion against future cracking from braking operations, providing beforehand protection against the harmful effects of repeated thermal and mechanical stress
3Strength
If crystal grains are aligned in rotating direction through ring rolling, then resistance to brake pad contact and crack prevention improve, but manufacturing process becomes more complex
Solution Approach 1:
The patent changes the physical parameters of the brake disc material through ring rolling, transforming the crystal grain structure to achieve enhanced strength and crack resistance while using controlled processing parameters to manage manufacturing complexity
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
The method results in a brake disc with increased durability and resistance to surface defects, extending its service life and reducing wear, as demonstrated by comparative testing showing lower wear rates for both the disc and brake pad.
Implementation Method 1
A manufacturing method involving ring rolling, followed by heat treatments and mechanical processes, to align crystal grains in the disc's rotating direction
Data Source
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AI summary
It is an object of the present disclosure to provide a manufacturing method of brake disc for railroad vehicles configured to enhance the life of brake disc with a new method. To this end, the method comprising: processing, in a ring shape, a structure comprised of carbon 0.20∼0.3 weight %, silicon 0.4∼0.7 weight %, manganese 0.35∼0.80 weight %, phosphorus less than 0.03 weight %, sulfur less than 0.03 weight %, nickel 0.5∼0.01 weight %, chrome 1.0∼1.5 weight %, molybdenum 0.7∼1.30 weight %, copper 0.3∼0.01 weight %, vanadium 0.2∼0.3 weight %, and rest being of iron (ring rolling process); performing a normalizing treatment of a structure processed through the ring rolling process (first heat treatment process); processing a surface of the structure finished with the first heat treatment process (first mechanical process); inspecting an inside defect through a non-destructive inspection of the structure finished with the first mechanical process (inspection process); performing a heat treatment of the structure finished with the inspection process (second heat treatment process); and processing the structure in a final disc shape (second mechanical process).