Testing standards
1, Geometric dimension detection standard
1. Track gauge: Track gauge refers to the distance between the inner sides of two parallel steel rails, usually 1435 millimeters. The deviation of track gauge will affect the smooth operation of the train, so it needs to be checked regularly.
2. Rail height: Rail height refers to the distance from the top surface of the rail to the bottom of the rail, and different types of rails have different rail height standards.
3. Bottom width of rail: Bottom width of rail refers to the width of the bottom of the rail, which affects the bearing capacity and stability of the rail.
4. Flatness: Flatness refers to the straightness of a steel rail within a certain length, which is related to the stability of the train and the wear of the rail.
2, Surface condition detection standard
1. Wear and tear: The surface wear of the steel rail will increase with the increase of use time, and regular testing is needed to ensure that it is within a safe range.
2. Cracks: Cracks on the surface of steel rails are potential safety hazards that require detection through methods such as ultrasonic testing.
3. Corrosion: Corrosion on the surface of steel rails can reduce their strength and durability, and requires regular cleaning and maintenance.
3, Internal defect detection standards
1. Internal cracks: Cracks inside the steel rail may not be easily detected, but they have a significant impact on the safety of the rail and require detection through methods such as magnetic particle testing and ultrasonic testing.
2. Internal voids: The voids inside the steel rail will reduce its load-bearing capacity and require detection through methods such as radiographic testing.
3. Material non-uniformity: The non-uniformity of rail materials can affect their performance and requires detection through methods such as spectral analysis.
4, Testing standards for rail joints
1. Joint smoothness: The smoothness of rail joints affects the smooth operation of trains, and it is necessary to ensure that the height difference and left and right misalignment at the joint are within the allowable range.
2. Joint strength: The strength of the rail joint needs to meet certain standards to ensure that it will not break when the train passes through.
5, Cycle and method of rail inspection
1. Regular inspection: Steel rails need to undergo comprehensive inspections regularly to ensure they meet the above standards.
2. Non destructive testing: Non destructive testing techniques such as ultrasonic testing, magnetic particle testing, etc. are widely used for detecting internal defects in steel rails.
3. Manual inspection: Manual inspection is the basic method of rail inspection, which can detect surface condition problems.
4. Automated detection: With the development of technology, automated detection equipment such as track inspection cars are being used to improve detection efficiency and accuracy.
6, International and national standards for rail inspection
1. International standards: Rail testing standards developed by international standardization organizations such as ISO and ASTM.
2. National standards: Steel rail inspection standards developed by each country based on their own railway operation conditions, such as GB/T 11264-2012 "Railway Steel Rails".
By conducting regular inspections and utilizing advanced testing techniques, issues with steel rails can be promptly identified and addressed, thereby ensuring the safety and efficiency of railway transportation.
