GB/T 3624-2010 Titanium and titanium alloy seamless tubes – China National Standard

Titanium and titanium alloy seamless tubes

Scope

This standard specifies the requirements, test methods, inspection rules, marking, packaging, transportation, storage, and contract contents for titanium and титановый сплав трубки. This standard applies to seamless titanium and titanium alloy tubes produced by cold rolling (cold drawing) and titanium and alloy tubes produced by welding and welding rolling methods.

This standard applies to titanium and alloy tubes used in the manufacture of heat exchangers, condensers, and various pressure vessels.

Normative References

The following documents, in their entirety, by reference in this standard, constitute the provisions of this standard. When referenced documents have dates of issue, subsequent amendments (excluding errata) or revisions do not apply to this standard. Однако, parties to agreements based on this standard are encouraged to investigate the possibility of using the most recent versions of these documents. When documents without dates of issue are referenced, the latest version applies to this standard.

• GB/T228 Test method for tensile test of metallic materials at room temperature
• GB/T 241 Test method for hydraulic test of metal tubes
• GB/T 242 Test method for expanding test of metal tubes
• GB/T246 Test method for flattening test of metal tubes
• GB/T3620.1 Grades and chemical composition of titanium and titanium alloys
• GB/T3620.2 Allowable deviations in chemical composition of titanium and titanium alloy processed products
• GB/T4698(All parts) Chemical analysis methods for sponge, titanium and titanium alloys
• GB/T8180 Packaging, marking, transportation and storage of titanium and titanium alloy processed products
• GB/T 12969 Ultrasonic and eddy current testing methods for titanium and titanium alloy tubes

Requirements

3.1 Product Classification

3.1.1 Оценка, State and Specification of Products

3.1.1.1 The grade, state and specification of cold-rolled seamless titanium and titanium alloy tubes shall comply with the provisions of Table 1

Table 1: Оценка, state and specification of cold-rolled seamless titanium and titanium alloy tubes

Оценка	State	Outer diameter (мм)	Wall thickness (мм)	Length (m)
TA0	A	≤40	≤1.6	≤8
	B	≤40	≤1.6	≤4
	С	≤40	≤1.6	≤2
	ЧАС	≤40	≤1.6	≤1
ТА1	A	≤40	≤2.0	≤8
	B	≤40	≤2.0	≤4
	С	≤40	≤2.0	≤2
	ЧАС	≤40	≤2.0	≤1
ТА2	A	≤40	≤3.0	≤8
	B	≤40	≤3.0	≤4
	С	≤40	≤3.0	≤2
	ЧАС	≤40	≤3.0	≤1
ТА3	A	≤40	≤1.6	≤8
	B	≤40	≤1.6	≤4
	С	≤40	≤1.6	≤2
	ЧАС	≤40	≤1.6	≤1
ТА9	A	≤40	≤2.0	≤8
	B	≤40	≤2.0	≤4
	С	≤40	≤2.0	≤2
	ЧАС	≤40	≤2.0	≤1
TA10	A	≤40	≤3.0	≤8
	B	≤40	≤3.0	≤4
	С	≤40	≤3.0	≤2
	ЧАС	≤40	≤3.0	≤1

3.1.1.2 The grade, state and specification of welded tubes shall comply with the provisions of Table 2.

Table 2: Оценка, state and specification of welded tubes

Оценка	State	Outer diameter (мм)	Wall thickness (мм)	Length (m)
TA0	A	≤168	≤4.0	≤12
	B	≤168	≤4.0	≤8
	С	≤168	≤4.0	≤6
	D	≤168	≤4.0	≤4
	E	≤168	≤4.0	≤2
	ЧАС	≤168	≤4.0	≤1
ТА1	A	≤168	≤5.0	≤12
	B	≤168	≤5.0	≤8
	С	≤168	≤5.0	≤6
	D	≤168	≤5.0	≤4
	E	≤168	≤5.0	≤2
	ЧАС	≤168	≤5.0	≤1
ТА2	A	≤168	≤6.0	≤12
	B	≤168	≤6.0	≤8
	С	≤168	≤6.0	≤6
	D	≤168	≤6.0	≤4
	E	≤168	≤6.0	≤2
	ЧАС	≤168	≤6.0	≤1
ТА3	A	≤168	≤4.0	≤12
	B	≤168	≤4.0	≤8
	С	≤168	≤4.0	≤6
	D	≤168	≤4.0	≤4
	E	≤168	≤4.0	≤2
	ЧАС	≤168	≤4.0	≤1
ТА9	A	≤168	≤5.0	≤12
	B	≤168	≤5.0	≤8
	С	≤168	≤5.0	≤6
	D	≤168	≤5.0	≤4
	E	≤168	≤5.0	≤2
	ЧАС	≤168	≤5.0	≤1
TA10	A	≤168	≤6.0	≤12
	B	≤168	≤6.0	≤8
	С	≤168	≤6.0	≤6
	D	≤168	≤6.0	≤4
	E	≤168	≤6.0	≤2
	ЧАС	≤168	≤6.0	≤1

3.1.1.3 The grade, state, and specification of titanium and titanium alloy tubes produced by the welding-rolling method shall comply with the provisions of Table 3.

Table 3: Welding-rolled tubes

Оценка	State	Outer diameter (мм)	Wall thickness (мм)	Length (m)
TA0	A	≤40	≤3.0	≤8
	B	≤40	≤3.0	≤4
	С	≤40	≤3.0	≤2
	ЧАС	≤40	≤3.0	≤1
ТА1	A	≤40	≤4.0	≤8
	B	≤40	≤4.0	≤4
	С	≤40	≤4.0	≤2
	ЧАС	≤40	≤4.0	≤1
ТА2	A	≤40	≤5.0	≤8
	B	≤40	≤5.0	≤4
	С	≤40	≤5.0	≤2
	ЧАС	≤40	≤5.0	≤1
ТА3	A	≤40	≤3.0	≤8
	B	≤40	≤3.0	≤4
	С	≤40	≤3.0	≤2
	ЧАС	≤40	≤3.0	≤1
ТА9	A	≤40	≤4.0	≤8
	B	≤40	≤4.0	≤4
	С	≤40	≤4.0	≤2
	ЧАС	≤40	≤4.0	≤1
TA10	A	≤40	≤5.0	≤8
	B	≤40	≤5.0	≤4
	С	≤40	≤5.0	≤2
	ЧАС	≤40	≤5.0	≤1

3.1.2 Marking Examples

Product marking is expressed in the order of product name, grade, production method, state, specification, and standard number. Examples of marking are as follows:

Пример 1:

TA2 cold-rolled seamless tube produced in accordance with this standard, annealed state, outer diameter 36mm, wall thickness 4mm, length 3000mm, marked as:

Pipe TA2 SM Ø36x4x3 000 GB/T 3625-2007

Пример 2:

TAI welded tube produced in accordance with this standard, annealed state, outer diameter 25mm, wall thickness 0.6mm, length 4000mm, marked as:

Pipe TAIWM Ø25×0.6×4 000 GB/T 3625-2007

Пример 3:

TAI welding-rolled tube produced in accordance with this standard, annealed state, outer diameter 19mm, wall thickness 0.5mm, length 4000mm, marked as:

Pipe TAIWR M19x0.5X4 000 GB/T 3625-2007

3.2 Dimensions and Dimensional Tolerances

3.2.1 The allowable tolerances for the outer diameter and wall thickness of tubes shall comply with the provisions of Table 4. The allowable tolerance for the wall thickness of tubes does not apply to the hot-formed joints of welded tubes.

Table 4 Allowable tolerances for outer diameter and wall thickness

Unit	Outer diameter (мм)	Wall thickness (мм)
≤25	±0.25	±0.12
25<D≤40	±0.30	±0.15
40<D≤60	±0.40	±0.18
60<D≤80	±0.50	±0.20
80<D≤100	±0.60	±0.25
100<D≤120	±0.70	±0.30
120<D≤140	±0.80	±0.35
140<D≤160	±0.90	±0.40
160<D≤200	±1.00	±0.45

3.2.2 The length of the tubes shall comply with the provisions of Table 5 and Table 6.

Table 5: Length of seamless and welded-rolled tubes

Unit	Outer diameter (мм)	Fixed length (мм)	Multiple length (мм)
≤40	≤8000	≤6000	≥6000
40<D≤60	≤6000	≤4000	≥4000
60<D≤80	≤4000	≤3000	≥3000
80<D≤100	≤3000	≤2000	≥2000
100<D≤120	≤2000	≤1500	≥1500
120<D≤140	≤1500	≤1000	≥1000
140<D≤160	≤1000	≤800	≥800
160<D≤200	≤800	≤600	≥600

Table 6: Length of welded tubes

Unit	Outer diameter (мм)	Fixed length (мм)	Multiple length (мм)
≤40	≤8000	≤6000	≥6000
40<D≤60	≤6000	≤4000	≥4000
60<D≤80	≤4000	≤3000	≥3000
80<D≤100	≤3000	≤2000	≥2000
100<D≤120	≤2000	≤1500	≥1500
120<D≤140	≤1500	≤1000	≥1000
140<D≤160	≤1000	≤800	≥800
160<D≤200	≤800	≤600	≥600

3.2.3 The fixed or multiple length of the tubes shall be within their non-fixed length range. When the fixed length is <6000мм, the allowable deviation is +60mm. When the fixed length is ≥6000mm, the allowable deviation is +10mm. The multiple length shall also include the cutting amount of the tubes, and the cutting amount for each cut shall be 5mm.

3.2.4 The ends of the tubes shall be cut flat and free of burrs, and the bevel shall comply with the provisions of Table 7.

Table 7: Bevel

Outer diameter (мм)	Angle of bevel (degrees)
≤40	30-45
40<D≤60	25-40
60<D≤80	20-35
80<D≤100	15-30
100<D≤120	10-25
120<D≤140	5-20
140<D≤160	3-15
160<D≤200	2-10

3.2.5 The straightness of the tubes shall comply with the provisions of Table 8.

Table 8: Straightness

Outer diameter (мм)	Maximum allowable deviation (мм) per meter length
≤40	2
40<D≤60	3
60<D≤80	4
80<D≤100	5
100<D≤120	6
120<D≤140	7
140<D≤160	8
160<D≤200	9

3.2.6 The out-of-roundness and non-uniform wall thickness of the tubes shall not exceed the allowable tolerances for the outer diameter and wall thickness.

3.3 Chemical Composition

The chemical composition of the products shall comply with the provisions of GB/T3620.1. When the purchaser performs a re-inspection, the allowable deviation of the chemical composition shall comply with the provisions of GB/T3620.2.

3.4 Mechanical Properties

3.4.1 The room temperature mechanical properties of the tubes in the supplied state shall comply with the provisions of Table 9. The non-proportional elongation strength Rp.02 shall only be tested when required by the purchaser and specified in the contract.

Table 9: Room temperature mechanical properties

Оценка	State	Tensile strength (МПа)	Yield strength (Rp.02) (МПа)	Elongation after fracture (%)
TA0	A	300-450	200-350	20
	B	300-450	200-350	20
	С	300-450	200-350	20
	ЧАС	300-450	200-350	20
ТА1	A	400-550	300-400	25
	B	400-550	300-400	25
	С	400-550	300-400	25
	ЧАС	400-550	300-400	25
ТА2	A	500-650	400-500	20
	B	500-650	400-500	20
	С	500-650	400-500	20
	ЧАС	500-650	400-500	20
ТА3	A	450-600	350-450	22
	B	450-600	350-450	22
	С	450-600	350-450	22
	ЧАС	450-600	350-450	22
ТА9	A	500-650	400-500	20
	B	500-650	400-500	20
	С	500-650	400-500	20
	ЧАС	500-650	400-500	20
TA10	A	550-700	450-550	18
	B	550-700	450-550	18
	С	550-700	450-550	18
	ЧАС	550-700	450-550	18

Processing Performance

3.5 Flattening Test

3.5.1.1 The tubes shall be subjected to a flattening test. When flattened to the specified gap, there shall be no cracks on the surface of the tubes.

The distance between the flattening plates shall be calculated according to the following formula:

(1+e)H = e+UD

Where:

H–Distance between flattening plates, in millimeters (мм); t–Nominal wall thickness of tube, in millimeters (мм); D–Nominal outer diameter of tube, in millimeters (мм); e–Constant, whose value is 0.07 for TA1, ТА2, ТА9, and TA9-1; 0.04 for TA3 when the tube diameter is less than or equal to 25.4 мм, и 0.06 for TA3 when the tube diameter is greater than 25.4 мм; 0.04 for TA10.

3.5.1.2 When the flattening test is performed on tubes with D/t < 10, due to geometric reasons, high stress is generated at the positions equivalent to “6 o’clock” and “12 o’clock” on the inner surface of the tubes. Поэтому, cracks generated at these positions shall not be used as the basis for rejection.

3.5.1.3 The flattening direction and weld position of welded tubes

3.5.1.4 Flaring Test

Welded tubes and welded-rolled tubes shall be subjected to a flaring test. After flaring, there shall be no cracks at the weld of the test piece.

3.5.2 Flaring Test

The tubes shall be subjected to a flaring test. The flaring shall be carried out with a tool with a 60° cone angle. When the expansion value of the inner diameter of the test piece after flaring meets the requirements of Table 10, there shall be no cracks in the test piece.

Table 10: Flaring Test

Оценка	State	Outer diameter (мм)	Expansion value (мм)
TA0	A, B, С, ЧАС	≤40	1.5t
	A, B, С, ЧАС	40<D≤60	1.2t
	A, B, С, ЧАС	60<D≤80	1.0t
	A, B, С, ЧАС	80<D≤100	0.8t
	A, B, С, ЧАС	100<D≤120	0.6t
	A, B, С, ЧАС	120<D≤140	0.5t
	A, B, С, ЧАС	140<D≤160	0.4t
	A, B, С, ЧАС	160<D≤200	0.3t
ТА1	A, B, С, ЧАС	≤40	1.8t
	A, B, С, ЧАС	40<D≤60	1.5t
	A, B, С, ЧАС	60<D≤80	1.3t
	A, B, С, ЧАС	80<D≤100	1.1t
	A, B, С, ЧАС	100<D≤120	0.9t
	A, B, С, ЧАС	120<D≤140	0.7t
	A, B, С, ЧАС	140<D≤160	0.6t
	A, B, С, ЧАС	160<D≤200	0.5t
ТА2	A, B, С, ЧАС	≤40	2.0t
	A, B, С, ЧАС	40<D≤60	1.8t
	A, B, С, ЧАС	60<D≤80	1.6t
	A, B, С, ЧАС	80<D≤100	1.4t
	A, B, С, ЧАС	100<D≤120	1.2t
	A, B, С, ЧАС	120<D≤140	1.0t
	A, B, С, ЧАС	140<D≤160	0.8t
	A, B, С, ЧАС	160<D≤200	0.7t
ТА3	A, B, С, ЧАС	≤40	1.6t
	A, B, С, ЧАС	40<D≤60	1.4t
	A, B, С, ЧАС	60<D≤80	1.2t
	A, B, С, ЧАС	80<D≤100	1.0t
	A, B, С, ЧАС	100<D≤120	0.8t
	A, B, С, ЧАС	120<D≤140	0.7t
	A, B, С, ЧАС	140<D≤160	0.6t
	A, B, С, ЧАС	160<D≤200	0.

3.5.3 Hydraulic (Pneumatic) Pressure Test

3.5.3.1 The tubes shall be subjected to a hydraulic or pneumatic pressure test. The test method chosen by the purchaser shall be specified in the contract. If not specified in the contract, the supplier shall choose the test method at its discretion.

3.5.3.2 For hydraulic tests, the test pressure chosen by the purchaser shall be specified in the contract. If not specified in the contract, the test pressure shall be calculated according to the following formula:

P = (D/2 – 0.48t)/SE

Where:

P–Test pressure, in megapascals (МПа); S–Allowable stress, take 50% of the minimum value of the specified non-proportional elongation strength, in megapascals (МПа); D–Nominal outer diameter of tube, in millimeters (мм); t–Nominal wall thickness of tube, in millimeters (мм); E–Constant, 1.0 for seamless tubes, 0.85 for welded tubes and welded-rolled tubes.

When the nominal outer diameter of the tube is not greater than 76 мм, the maximum pressure for the hydraulic test shall not be greater than 17.2 МПа; when the nominal outer diameter of the tube is greater than 76 мм, the maximum pressure for the hydraulic test shall not be greater than 19.3 МПа. The pressure shall be maintained for 5 s during the test, and the tubes shall not deform or leak.

3.5.3.3 For pneumatic tests, the internal air pressure test pressure of the tubes shall be 0.7 МПа. The pressure shall be maintained for 5 s during the test, and the tubes shall not deform or leak.

3.6 Non-Destructive Testing

Tubes with an outer diameter of 10 mm to 60 mm shall be subjected to ultrasonic or eddy current testing, and shall comply with the provisions of GB/T12969. The testing method chosen by the purchaser shall be specified in the contract. If not specified in the contract, the supplier shall determine one method for testing at its discretion. For other specifications of tubes, ultrasonic or eddy current testing shall be carried out at the discretion of both parties.

3.7 Appearance Quality

3.7.1 The inner and outer surfaces of the tubes shall be clean and free of visible defects such as cracks, folds, peeling, and pinholes. The welds of welded tubes shall be fully filled and smoothly transitioned.

3.7.2 Local defects on the surface of the tubes may be removed, but the removal shall not cause the outer diameter and wall thickness to exceed their allowable tolerances.

3.7.3 The surface of the tubes may have scratches, dents, bumps, and straightening marks that do not exceed the allowable tolerances for outer diameter and wall thickness. Different colors are allowed on the surface of the tubes after pickling.

4.1 Referee Analysis Method for Chemical Composition

The referee analysis of the chemical composition of the tubes shall be carried out in accordance with GB/T4698.

4.2 Mechanical Properties Test Methods

4.2.1 The room temperature tensile test method for tubes shall be carried out in accordance with GB/T228.

4.2.2 For tubes with an outer diameter not greater than 35 мм, the S8 test piece in GB/T228 shall be used; for tubes with an outer diameter greater than 35 мм, the S4 test piece shall be used.

4.3 Processing Performance Test Methods

4.3.1 The hydraulic test for tubes shall be carried out in accordance with GB/T241.

4.3.2 The pneumatic pressure test for tubes shall be carried out in accordance with a method agreed upon by the purchaser and the supplier.

4.3.3 The flaring test for tubes shall be carried out in accordance with GB/T242.

4.3.4 The flattening test for tubes shall be carried out in accordance with GB/T246.

4.4 Non-Destructive Testing Methods

For tubes with dimensions within the scope of GB/T12969, ultrasonic and eddy current testing shall be carried out in accordance with GB/T12969. For tubes with dimensions beyond the scope of GB/T12969, manual ultrasonic testing methods may be used.

4.5 Dimensional Measurement Methods

The dimensional inspection of tubes shall be carried out with measuring instruments of appropriate accuracy.

4.6 Appearance Quality Inspection Method

The appearance quality inspection of tubes shall be carried out by visual inspection.

5.1 Inspection and Acceptance

5.1.1 The products shall be inspected by the supplier’s quality inspection department to ensure that the product quality meets the requirements of this standard or the contract, and a quality certificate shall be filled out.

5.1.2 The purchaser shall accept the products received in accordance with the provisions of this standard. If the inspection results do not conform to the provisions of this standard, the purchaser shall raise an objection to the supplier within three months from the date of receipt of the products, and the two parties shall negotiate a solution. If arbitration is required, the sampling for arbitration shall be jointly carried out by the purchaser and the supplier.

5.2 Groups and Batches

Products shall be submitted for acceptance in batches, and each batch shall consist of products of the same grade, heat number, specification, manufacturing method, state, and from the same heat treatment furnace.

5.3 Inspection Items

Each batch of products shall be subjected to inspection of chemical composition, dimensional tolerance, mechanical properties, processing performance, non-destructive testing, and appearance quality. The inspection items specified in the contract shall also be subjected to inspection.

5.4 Sampling Location and Sampling Quantity

The sampling of products shall comply with the provisions of Table 11.

Table 11 Sampling Location and Sampling Quantity

Item	Sampling Location	Sampling Quantity
Химический состав	From each batch, take a sample from each heat treatment furnace batch and analyze one sample for each element.	1
Dimensional deviation	From each batch, take 1% of the products for inspection, but not less than 2 pieces.	As needed
Mechanical properties	From each batch, take 1% of the products for inspection, but not less than 2 pieces.	As needed
Processing performance	From each batch, take 1% of the products for inspection, but not less than 2 pieces.	As needed
Non-destructive testing	From each batch, take 100% of the products for inspection.	As needed
Appearance quality	From each batch, take 100% of the products for inspection.	As needed

5.5 Retesting and Judgment of Inspection Results

5.5.1 If the chemical composition is not qualified, the batch shall be judged as unqualified.

5.5.2 In the room temperature mechanical properties test, flattening test, and flaring test, if the test result of one test piece is not qualified, then double test pieces shall be taken from the batch to repeat the test for the unqualified items. If the test result of the repeat test is still unqualified for one test piece, then the batch of products shall be judged as unqualified. Однако, the supplier may inspect each product individually for the unqualified items, and those that are qualified shall be regrouped.

5.5.3 If the dimensions and shape, surface quality, hydraulic test, and ultrasonic test of the tubes are not qualified, the single tube shall be judged as unqualified.

6 Marking, Упаковка, Transportation and Storage

6.1 Marking

The following marks shall be made on the inspected and packaged tubes and cartons:

a) Product grade; b) Product name; c) Supply status; d) Batch number; e) This standard number.

6.2 Упаковка, Transport and Storage

The packaging, transport and storage of products shall comply with the relevant provisions of GB/T8180.

6.3 Quality Certificate

A quality certificate shall be attached to each batch of tubes, indicating:

a) Name of the supplier; b) Product name; c) Product grade, specification, manufacturing method and state; d) Heat number, batch number, batch weight and number of pieces; e) Analysis and inspection results and quality inspection department seal; f) This standard number; g) Packing date.

7 Content of Order Form (or Contract)

The order form (or contract) for ordering the materials listed in this standard shall include the following contents:

a) Product name; b) Оценка; c) State; d) Dimensional specifications; e) Weight or number of pieces; f) Working pressure for hydraulic test; g) Ultrasonic or eddy current testing; h) This standard number; i) Others.