GB/T 41750-2022Titanium and titanium alloy square and rectangular tubes (English PDF)

5.1 Base metal

The plates used for welding square tubes and rectangular tubes shall meet the requirements of the corresponding grades of plates in GB/T 3621, and shall be accompanied by a quality certificate.

5.2 Chemical composition

5.2.1 The chemical composition of the product shall meet the requirements of GB/T 3620.1.

5.2.2 When the buyer takes samples from the product for chemical composition retesting, the allowable deviation of the chemical composition shall comply with the provisions of GB/T 3620.2.

5.3 Dimensions and their allowable deviations

5.3.1 The dimensions of the product and their allowable deviations shall comply with the provisions in Table 2.

5.3.2 The side concavity and convexity X1 and X2 of the product shall not exceed 1.5% of the side length. Indented dimensions are not included in the dimension tolerances.

5.3.3 The curvature of the product shall not exceed 2 mm/m, and the total curvature shall not exceed 0.15% of its length.

6.3 Tensile properties

The test of the tensile properties of the product at room temperature shall be carried out according to the method specified in GB/T 228.1.

6.4 Penetration test

The penetration test of the product shall be carried out according to the method specified in NB/T 47013.5-2015.

6.5 Appearance quality

The test of the appearance quality of the product shall be carried out by visual inspection.

7.1 Inspection and acceptance

7.1.1 Products shall be inspected by the supplier or a third party.

7.1.2 The buyer can inspect the received products according to the provisions of this document. When the inspection results are inconsistent with the provisions of this document or the purchase order, it shall be reported to the supplier in written form, and the supplier and the buyer shall negotiate to resolve it. Objections pertaining to dimensions and their allowable deviations, penetration test and appearance quality shall be raised within one month from the date of receipt of the product; objections pertaining to chemical composition and tensile properties shall be raised within three months from the date of receipt of the product. If arbitration is required, the supply and demand parties shall sample jointly on the demand side, or it shall be negotiated by the supply and demand parties.

7.2 Batching

double samples shall be taken from this batch of products for repeated inspection. If there is still an unqualified sample in the repeated inspection, the batch of products shall be judged as unqualified. However, the supplier can inspect the pipes one by one, and the qualified ones can be delivered in batches again.

8.1 Marking

8.1.1 Product marking

Labels or tags shall be attached to the products that have passed the inspection, and the following contents shall be indicated at least on them:

a) The name and trademark of the manufacturer;

b) Grade;

c) Specifications;

d) State;

e) Batch number;

f) Number of this document.

8.1.2 Packaging marks

The packaging marks of the products shall comply with the provisions of GB/T 8180.

8.2 Packaging, transportation, and storage

The packaging, transportation, and storage of the products shall comply with the provisions of GB/T 8180.

8.3 Accompanying documents

Each batch of products shall be attached with accompanying documents, which shall not only include supplier information, product information, serial number of this document, date of manufacture or date of packaging, but also include:

a) Quality certificate, the contents are as follows:

- Product name, grade, specification, and state; […]