解析
GB 6653-94 Welding Cylinder Steel Plate
This standard GB 6653-94 provides requirements, test methods, inspection rules and packaging, marking, quality of welding steel plates for manufacturing various types of gas cylinders.
1. Scope
This standard applies to welded steel plates are used to manufacture gas cylinders with a volume of 5ℓ nor more than 150ℓ.
2. Normative References
The following documents become part of the conditions of this standard as required. For undated references, the latest edition of the documents applies.
GB/T228.1-2003 Tensile test methods for metals – (Part 1: Mechanical Properties Testing Round Steel Specimen).
GB/T422.1-2008 Rolling test method for sheets and strips – Part 1: Determination of yield point, tensile strength, elongation and reduction of area.
GB/T1750-2009 Metallic materials - Frech bend test piece and curved manchine test piece
3. Terms and definitions
3.1 Production Standards
The production standards refer to the industrial producing standard of welding steel plates used in manufacturing welding cylinders, which has been worked out according to the classification, size and wall thickness of cylinders.
3.2 Welding Steel Plate
Welding steel plate is the steel plate which used for welding cylinder. Its steel plate chemical and physical properties should be comply with the requirement of this standard, and its size should meet the production standards.
4. Requirements
4.1 Chemical composition
The chemical composition (see Table 1) of each welding steel plates must meet the requirements when delivery and within the allowed variation range after deformation, annealing and normalizing.
Table 1 Chemical composition (mass fraction %) Grade C Si Mn P S ULTRA-LOW CARBON ≤0.17 0.10-0.45 0.50-1.00 ≤0.06 ≤0.035 LOW CARBON ≤0.20 0.10-0.45 0.50-1.00 ≤0.06 ≤0.035 MEDIUM CARBON ≤0.23 0.10-0.55 0.50-1.00 ≤0.06 ≤0.035
4.2 Delivery status and testing requirements
(1) The delivery status of all the welding steel plates should be in accordance with the requirements in Table 2.
Table 2 Delivery status
Delivery status Testing Item Requirement Deformation Hot roll Z-Test hardness HRC≥35 Annealing Bending strength and Elongation BWB≥485MPa A2≥ 22% Normalizing CVN≥52J
(2) The requirements of the deformation are that after hot rolling, the direction of the rolling lines should be parallel to the rolling direction of the middle layers, no percussion and defects of its surface should exist, and the residue of iron scale should eliminate in time.
(3)The requirements of the annealing are that the sample should be heated to 700～730℃, soaking for one hour, cooling in the furnace and then take the sample test.
(4)The requirements of the normalizing are that the sample should be heated to 980～1020℃, soaking for one hour, cooling in the air and then take the sample test.
4.3 Size
(1) The nominal width of the steel plate should meet the size requirements of production standards.
(2) The diagonal size of the steel plate is allowed to be 2.5% larger than the requirements.
4.4 Heat Treatment Quality
(1) Hot Rolling Core Tolerance: the tolerance of the depth of the cold deformation should not exceed 7.5mm., the tolerance of the cold dents should not exceed 5mm, and the tolerance of the shape-deviation should not exceed 5mm.
(2) Bending Strength and Elongation: the minimum bending strength, yield strength, minimum elongation and plasticity reduction of all welded cylinders must be meet the requirements, that are respectively not lower than 485MPa, not lower than 315MPa, not lower than 22% and not lower than 28%.
(3) Charpy Impact Test: Charpy Impact Test results must meet the requirements, and the average value of the sample to reach not lower than 80J, the maximum value not lower than 60J.
5. Test Methods
5.1 Chemical analysis
For all welding steel plate, verify its chemical composition, according to the relevant requirements in Table 1 of this standard.
5.2 Mechanical properties
Testing the welding steel plates mechanical properties, complying with the requirements of GB/T228.1-2003, GB/T422.1-2008, GB/T1750-2009.
5.3 Size
Measuring the welded cylinders diagonal size and examine whether is qualified, through its accords with the size requirements or not.
6. Inspection Rules
6.1 Quality Inspection
The inspection process of welding steel plates through its quality, chemical composition, delivery status and mechanical properties; compliance with the requirements of this standard. If a batch inspection results of the welding steel plates failed, a re-inspection is required.
6.2 Statistical Inspection
From each batch of welding steel plates, draw five sample tablets at random, examining their quality, chemical composition, delivery status and mechanical properties; compliance with the requirements of this standard.
7. Packaging, Marking & Quality Certificate
7.1 Packaging
(1) The welding steel plates should packaged in the bundles firmly, which further put the material in the box, It can not be directly exposed to rain and sunshine.
(2) The welding steel plates should be listed without fail, cleaned and rust removal
7.2 Marking
In each plate should be marked as follows:
(1) steel plate model;
(2) manufacturers Name or its Abbreviation;
(3) batch number;
(4) steel plate size;
(5) The maximum wall thickness of the cylinder made by it.
7.3 Quality Certificate
The Manufacturer shall provide necessary Quality Certificate in accordance with this Standard while delivery.
Conclusion:
This standard GB 6653-94 is applicable to requirements, test methods, inspection rules and packaging, marking, quality of welding steel plates for manufacturing various types of gas cylinders. The chemical composition, delivery status and the size requirements, heat treatment quality and mechanical properties along with inspection rules for welding steel plate are included in this standard. In addition, the packaging, marking and quality certificate requirements for welding steel plate are also given in this standard. The purpose of GB 6653-94 is to ensure the quality and safety of welding cylinders manufactured from welding steel plates.
