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About us
Tianjin lefin Industrial
TIANJIN LEFIN STEEL GROUP containing Tianjin lefin Industrial Co.,Ltd. 、Tianjin lefin steel import & export Co.,Ltd and Tianjin Shengqifeng International Trading Co., Ltd. -
Products
Steel Pipe Processing
Our main products include 1/2inch to 16 inch ERW PIPE/GI PIPE which has been produced according to BS1387/ASTM A53/EN10219/EN10255/EN10217 Standard -
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Service Capability
Guarantee Quality
Our steel pipes are suitable for oil, natural gas, shipbuilding, chemical industry, water conservancy, electrical, steel structure, construction and other related fields.
- Details
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The requirements for seamless mechanical pipes (PIPE) in ASTM A519 standard cover multiple dimensions such as material, mechanical properties, dimensional tolerance, and processing technology. The core is to ensure that they meet the structural strength, processing adaptability, and dimensional stability requirements in mechanical manufacturing. The following is a summary of the key requirements:
I. Material and Chemical Composition Requirements
1. Material range
Covering carbon steel and alloy steel, common grades include:- Carbon steel:1010, 1020, 1026, 1045, etc. (low carbon to medium carbon steel, emphasizing machinability and toughness);
- Alloy steel: 4130, 4140, 4340, etc. (containing alloying elements such as chromium and molybdenum, emphasizing high strength and wear resistance).
2. Chemical composition restrictions
For elements such as carbon (C), manganese (Mn), silicon (Si), phosphorus (P), and sulfur (S), there are clear upper limits (for example, sulfur content ≤0.050%, phosphorus content ≤0.040%). Alloy steel also needs to control the content range of alloying elements such as chromium and molybdenum to ensure the stability of mechanical properties.II. Mechanical Property Requirements
This is the core requirement of ASTM A519, which is directly related to the load-bearing capacity of the pipe material:
- Tensile strength: Depending on the material, the range is usually 330-795 MPa (for example, 1020 steel ≥379 MPa, 4140 steel ≥655 MPa);
- Yield strength: ≥207 MPa (low-carbon steel) to ≥414 MPa (alloy steel);
- Elongation: ≥5% for cold-worked pipes and ≥10% for hot-worked pipes (to ensure certain toughness and avoid brittle fracture);
- Hardness: Some grades must meet the Brinell hardness (HB) requirements (for example, the HB of 4140 steel after heat treatment should be ≤235).
Note: It needs to be verified through tensile tests and hardness tests, and the test samples should be taken from the pipe body.
III. Dimensions and Tolerance Requirements
To adapt to precision mechanical processing, strict requirements are imposed on dimensional accuracy:
1. Outer diameter (OD) :
- Cold-worked tubes: Tolerance range ±0.005 inches (small diameter) to ±0.010 inches (large diameter);
- Hot-worked tubes: Slightly wider tolerance (±0.031 inches when outer diameter ≤2 inches).
2. Wall thickness (WT) :
- Cold-worked pipe: Tolerance ±10% (±5% for some specifications);
- Hot working tubes: Tolerance ±12.5%.
3. Straightness:The bending degree per foot length is ≤0.015 inches, ensuring that it is not prone to deformation during processing.
4. Length:Usually 6 to 24 feet, customizable as required, but must meet the flatness requirements.
IV. Processing Technology and Surface Quality
1. Production Process:
- Must be seamless formed (hot rolling, cold drawing or cold rolling), welding is prohibited (distinguished from welded pipes);
Cold-worked tubes need to undergo annealing treatment to eliminate processing stress and ensure dimensional stability.
2. Surface quality :
The inner and outer surfaces should be smooth, free of cracks, folds, scars and other defects (which affect processing and strength).
Minor scratches are allowed, but the depth must not exceed 10% of the wall thickness tolerance.V. Inspection and Marking Requirements
1. Inspection Items
- Check the size and appearance of each piece one by one;
Chemical composition analysis and mechanical property tests (tensile and hardness) were conducted by batch sampling.
For high-pressure applications or critical components, additional non-destructive testing (such as ultrasonic flaw detection) is required.
2. Marking Requirements :
Each pipe material should be marked with the standard number (ASTM A519), material grade, specification, manufacturer's identification, inspection qualification identification, etc., for easy traceability.
ASTM A519 PIPE
Subcategory
Keyword
- Details
-
The requirements for seamless mechanical pipes (PIPE) in ASTM A519 standard cover multiple dimensions such as material, mechanical properties, dimensional tolerance, and processing technology. The core is to ensure that they meet the structural strength, processing adaptability, and dimensional stability requirements in mechanical manufacturing. The following is a summary of the key requirements:
I. Material and Chemical Composition Requirements
1. Material range
Covering carbon steel and alloy steel, common grades include:- Carbon steel:1010, 1020, 1026, 1045, etc. (low carbon to medium carbon steel, emphasizing machinability and toughness);
- Alloy steel: 4130, 4140, 4340, etc. (containing alloying elements such as chromium and molybdenum, emphasizing high strength and wear resistance).
2. Chemical composition restrictions
For elements such as carbon (C), manganese (Mn), silicon (Si), phosphorus (P), and sulfur (S), there are clear upper limits (for example, sulfur content ≤0.050%, phosphorus content ≤0.040%). Alloy steel also needs to control the content range of alloying elements such as chromium and molybdenum to ensure the stability of mechanical properties.II. Mechanical Property Requirements
This is the core requirement of ASTM A519, which is directly related to the load-bearing capacity of the pipe material:
- Tensile strength: Depending on the material, the range is usually 330-795 MPa (for example, 1020 steel ≥379 MPa, 4140 steel ≥655 MPa);
- Yield strength: ≥207 MPa (low-carbon steel) to ≥414 MPa (alloy steel);
- Elongation: ≥5% for cold-worked pipes and ≥10% for hot-worked pipes (to ensure certain toughness and avoid brittle fracture);
- Hardness: Some grades must meet the Brinell hardness (HB) requirements (for example, the HB of 4140 steel after heat treatment should be ≤235).
Note: It needs to be verified through tensile tests and hardness tests, and the test samples should be taken from the pipe body.
III. Dimensions and Tolerance Requirements
To adapt to precision mechanical processing, strict requirements are imposed on dimensional accuracy:
1. Outer diameter (OD) :
- Cold-worked tubes: Tolerance range ±0.005 inches (small diameter) to ±0.010 inches (large diameter);
- Hot-worked tubes: Slightly wider tolerance (±0.031 inches when outer diameter ≤2 inches).
2. Wall thickness (WT) :
- Cold-worked pipe: Tolerance ±10% (±5% for some specifications);
- Hot working tubes: Tolerance ±12.5%.
3. Straightness:The bending degree per foot length is ≤0.015 inches, ensuring that it is not prone to deformation during processing.
4. Length:Usually 6 to 24 feet, customizable as required, but must meet the flatness requirements.
IV. Processing Technology and Surface Quality
1. Production Process:
- Must be seamless formed (hot rolling, cold drawing or cold rolling), welding is prohibited (distinguished from welded pipes);
Cold-worked tubes need to undergo annealing treatment to eliminate processing stress and ensure dimensional stability.
2. Surface quality :
The inner and outer surfaces should be smooth, free of cracks, folds, scars and other defects (which affect processing and strength).
Minor scratches are allowed, but the depth must not exceed 10% of the wall thickness tolerance.V. Inspection and Marking Requirements
1. Inspection Items
- Check the size and appearance of each piece one by one;
Chemical composition analysis and mechanical property tests (tensile and hardness) were conducted by batch sampling.
For high-pressure applications or critical components, additional non-destructive testing (such as ultrasonic flaw detection) is required.
2. Marking Requirements :
Each pipe material should be marked with the standard number (ASTM A519), material grade, specification, manufacturer's identification, inspection qualification identification, etc., for easy traceability.
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Address: Hengtai Road,Daqiuzhuang Town,Jinghai County,Tianjin,China
Mob: +8615122229899(whatspp)
Phone: +86 22 58171905
Fax: +86 22 58171902
E-mail:info@lefinsteel.com
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