Adjustable Air Cooling Headers for Uniform Rail Hardening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for manufacturing high-hardness rails with a fine pearlite structure face challenges such as increased running costs, high initial investment costs, and potential deterioration of toughness and wear resistance due to localized cooling rate variations, leading to undesirable structural transformations like martensite or bainite.
Innovation Solution
A cooling apparatus and method that uses adjustable cooling headers and flow control units to precisely manage cooling rates and distances, ensuring at least 98% pearlite structure formation in rails, with air as the cooling medium, minimizing costs and maintaining high hardness and toughness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the jet flow rate of the cooling medium is increased to intensify cooling, then the hardness of the rail surface and interior is improved, but the running cost of the blower increases
Solution Approach 1:
The patent changes the physical parameters of the cooling medium (from water to air or gas) and adjusts cooling intensity through flow rate control and multi-stage cooling processes, achieving the desired hardness while reducing energy consumption and operating costs compared to conventional water cooling methods
2Strength
If cooling with mist is performed to achieve high hardness, then the hardness of the rail is improved, but the initial investment cost increases due to water supply and drainage facilities
Solution Approach 1:
The patent replaces expensive water-based cooling systems with air or gas cooling, eliminating the need for complex water supply and drainage infrastructure while achieving the same hardening effect, thereby reducing initial investment costs
Solution Approach 2:
The patent uses pneumatic cooling (air or gas flow) instead of hydraulic cooling (water), simplifying the system by eliminating water handling equipment while maintaining effective cooling capability for achieving high hardness
3Strength
If cooling to low temperature is performed to increase hardness, then the hardness is improved, but cold spots are generated causing local increase in cooling rate that transforms structure to martensite or bainite, deteriorating toughness and wear resistance
Solution Approach 1:
The patent applies different cooling intensities to different regions of the rail through multi-stage cooling processes, ensuring uniform cooling across the rail cross-section and preventing localized cold spots that would cause unwanted martensite or bainite transformations, thereby maintaining both hardness and toughness
Solution Approach 2:
The patent employs periodic or multi-stage cooling processes with controlled cooling rates, allowing the rail to cool uniformly through different temperature ranges and avoiding sudden temperature drops that create cold spots and undesirable microstructures
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 apparatus and method enable cost-effective production of rails with high hardness and toughness by ensuring uniform cooling across the rail structure, reducing running and initial investment costs while avoiding structural deterioration.
Implementation Method 1
the head top face, head side, foot underside portion, and, in addition, web portion, as needed, of the rail are forcibly cooled by air as a cooling medium
Implementation Method 2
the flow rate of a cooling medium is increased after the time at which a temperature history gradient becomes gentle due to generation of heat of transformation
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
There are provided an apparatus for cooling a rail and a method for manufacturing a rail, capable of inexpensively manufacturing a rail with high hardness and high toughness. The apparatus (2) for cooling a rail, configured to jet a cooling medium to the head portion (11) and foot portion (12) of a rail (1) in an austenite temperature range to forcibly cool the rail (1), includes: a first cooling unit (21) including plural first cooling headers (211a to 211c) configured to jet the cooling medium as gas to the head top face and head side of the head portion (11), and first driving units (213a to 213c) configured to move at least one first cooling header (211a to 211c) of the plural first cooling headers (211a to 211c) to change the jet distance of the cooling medium jetted from the first cooling header (211a to 211c); and a second cooling unit (22) including a second cooling header (221) configured to jet the cooling medium as gas to the foot portion (12).