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This standard is issued under the fixed name A 554;

1. Scope

1.1 This specification covers welded stainless steel pipes for mechanical applications that need appearance, mechanical properties, or corrosion resistance. Table 1 lists the levels covered.
1.2 This specification covers welded or cold-rolled mechanical pipes with a size of 16 inches (406.4 mm) and size of 0.020 inches (0.51 mm) and above.
1.3 The test tube should be installed according to one of the following shapes specified by the buyer: round, square, rectangular or special shape.
1.4 Optional supplementary requirements are provided, which should be indicated in the order when necessary.
1.5 The value in inch-pound units shall be regarded as the standard value. The values given in parentheses are for reference only.

2. Reference documents

2.1 ASTM standards: 2

A370 Test methods and definitions for mechanical testing of steel products
est methods for chemical analysis of E30 steel, cast iron, pig iron and wrought iron 3
E59 Operating Rules for the Determination of Chemical Composition of Steel Samples 3

2.3 Federal Standards:

Fed Standard No. 123 Cargo Marking (Civil Administration) 4

3. Ordering information

3.1 Material orders under this specification should be include the following as needed to fully describe the required materials:
3.1.1 Quantity (feet, mass or number of pieces),
3.1.2 Material name (welded stainless steel mechanical tube)
3.1.3 form (circle, square, rectangle, special shape, please refer to 1.3),
3.1.4 Dimensions:
3.1.4.1 The outer diameter and wall thickness under all conditions (Section 8). Or, for cold shrink conditions, you can specify outer and inner diameters or inner diameters and wall dimensions,
3.1.4.2 The external dimensions and wall thickness of squares and rectangles (see 9.1),
3.1.4.3 Special (to be specified),
3.1.5 Length (mill length, cutting length or multiple lengths (see 8.3)),
3.1.6 Grade (Table 1),
3.1.7 Conditions (see 6.1),
3.1.8 The condition of the inner diameter weld bead (see 6.2),
3.1.9 Surface treatment (see section 11),
3.1.10 If necessary, make a chemical analysis report (Section 7),
3.1.11 Individual supplementary requirements (if needed),
3.1.12 end use,
3.1.13 canonical name,
3.1.14 special requirements,
3.1.15 special markings (section 14), and
3.1.16 Special packaging (Section 15).

4. Process

4.1 Steel can be manufactured by any method.
4.2 If the buyer requires a specific type of melting, it should be noted on the purchase order.
4.3 The initial meeting can be degassed or refined separately and then can be remelted, such as remelting or vacuum arc remelting. If secondary melting is used, the heat quantity should be defined because all ingots are remelted from the primary melting.
4.4 Steel can be cast into ingots or into bars. When casting different grades of steel sequentially, the resulting transition material needs to be identified. Producers should actively separate transition materials in accordance with established steps to eliminate differences between grades.

5. Material and manufacturing

5.1 The pipe shall be made of flat-rolled steel through an automatic welding process, and no filler metal shall be added.

6. Conditions

6.1 The test tube should be installed under any of the following specified conditions:
6.1.1 When welding
6.1.2 Welding and annealing,
6.1.3 Reduce cooling capacity
6.1.4 Reduce the cooling capacity and anneal.
6.2 The inner diameter bead shall be installed under any of the following specified conditions:
6.2.1 The beads are not removed,
6.2.2 The weld seam is controlled to 0.005 inches (0.13 mm) or 15% of the specified wall thickness, whichever is greater
6.2.3 Remove the beads.

7. Thermal analysis

7.1 The steel manufacturer shall analyze the heat of each type of steel to determine the percentage of the specified element. If a secondary melting process is used, the thermal analysis should be obtained from the product of one remelted ingot for each main melt. The chemical composition thus determined, or the chemical composition determined by the product analysis performed by the tubular product manufacturer shall meet the specified requirements. When required in the order or contract, this analysis report shall be provided to the buyer.

8. Allowable changes in size-round tube

8.1 For all conditions, except for the pipe material from which the bead is removed, Table 2 shall apply.
8.2 For pipes with strips removed, Table 3 shall apply.
8.3 Length—The length of the tubing is usually 5 feet (1.5 m) and above. If specified, provide a clear cut length to achieve the length tolerance shown in Table 4. For pipes ordered in multiple lengths, the usual practice is to determine a clear quantity for each multiple in the buyer’s cutting operation. Therefore, the reduction allowance should be specified in the purchase order.
8.4 Straightness tolerance-In any 3-foot (0.9-m) pipe, the straightness tolerance should be a maximum of 0.030 inches (0.76 mm). The shorter length and the straightness tolerance for special requirements should be negotiated between the purchaser and the manufacturer.

9. Allowable changes in a size-square tube and rectangular tube

9.1 Square and rectangular welding stainless steel machinery Unless otherwise stated, the pipes are cold worked. For this pipe, its size is different from the specified size must not exceed the quantity specified in Table 5. For length, See 8.3.

10. Craftsmanship, appearance, and appearance

10.1 The end of the finished pipe should be smooth and free of burrs. They should be free from harmful defects and have a worker-like finishing effect. If surface defects can be removed within 10% of the specified wall or within 0.002 inches (0.05 mm), surface defects (such as processing marks, straightening marks, light mandrel and mold marks, shallow pits, and scale patterns) will not be removed Considered a serious defect. ,Whichever is greater. Unless a special refinish paint is specified, there is no need to remove surface defects.

11. Surface treatment

11.1 The test tube must be free of scale.
11.2 If special surface treatment is required, it should be indicated in the order

12. Reject

12.1 Tubing that does not meet the requirements of this specification shall be shelved and the manufacturer shall be notified.

13. Coating

13.1 Stainless steel pipes usually have no protective coating when they leave the factory. If special protection is required, the details should be specified in the order.

14. Packaging

14.1 Civil procurement-the pipeline is 0.065 inches. (1.65mm) walls and lighters, manufacturers can choose to pack boxes, crates, cartons, and cartons in a safe lift or strap to ensure safe delivery. The tubing is heavier than 0.065 inches. The walls are usually shipped in bulk, strapped, or fixed in a lift. Special packaging that requires additional operations in addition to the packaging normally used by the manufacturer must be specified in the order.

15. Keywords

15.1 Austenitic stainless steel; mechanical oil pipe; stainless steel pipe; steel pipe; welded steel pipe

Test methods and definitions A 370.

S1. Hardness Testing

The S1.1 round annealed tube shall meet the hardness limit requirements specified in Table S1.1. Note that S1-the diameter, wall, or combination of certain tubes can limit the applicability of certain hardness values.
When hardness is specified in S1.2, a test tube of 2500 feet (760 m) or a part of each steel should be tested for hardness of the sample.

S2. Stretching test

The S2.1 pipe shall meet the tensile performance requirements specified in Table S2.1. When ordering reduced temperature tempering, the manufacturer should be consulted.
S2.2 When the tensile test is specified, one sample should be drawn from each test tube of 2500 feet (760 m) or a part of the sample from each batch of steel before being cut to a certain length. test.
S2.3 will determine the yield strength under load corresponding to a permanent offset of 0.2% of the gauge length or a total extension of 0.5% of the gauge length.

S3. Non-destructive testing

S3.1 can use various types of non-destructive testing. When any such tests are required, the test and inspection limits to be used shall be specified in the order.

S4. testing report

When specified in the order, the S4.1 Mill test report will be provided.
S4.1 When it is clearly specified in the purchase order, or when a specific type of melting is specified, the type of melting used to produce the material should be included in the test report.
S4.2 When a material that fails in any molding operation or installation process is found to be defective, it should be put aside, and the manufacturer should be notified to evaluate the applicability of the material to each other. Disposal of such materials should be agreed upon by agreement.