GB/T 3090-2020Seamless small diameter stainless steel tubes (English PDF)

Foreword

This Standard was drafted as per the rules specified in GB/T 1.1-2009.

This Standard replaced GB/T 3090-2000 Stainless Steel Small Diameter Seamless Steel Tubes. Compared with GB/T 3090-2000, this Standard made the major technical changes as follows:

--- Modify the normative references (see Clause 2 of this Edition; Clause 2 of the 2000 Edition);

--- Modify the classification method (see Clause 3 of this Edition; Clause 3 of the 2000 Edition);

--- Add the ordering content (see Clause 4 of this Edition);

--- Add the size specifications of the steel tube (see Table 1 of this Edition);

--- Delete the mark example (see 4.6 of 2000 Edition);

--- Modify the requirements for normal length (see 5.3.1 of this Edition; 4.3.1 of 2000 Edition);

--- Modify the requirements for the specified length and multiple length (see 5.3.2 of this Edition; 4.3.2 of 2000 Edition);

--- Modify the steel designation representation method and chemical composition (see Table 3 of this Edition; Table 3 of 2000 Edition);

--- Add the steel smelting method and steel tube manufacturing method (see 6.2 of this Edition);

--- Modify the delivery status requirements (see 6.3 of this Edition; 5.2 of 2000 Edition);

--- Add the mechanical performance requirements of steel tubes delivered in hard state (see 6.4 of this Edition);

--- Modify the mechanical properties of the steel tube and steel density (see Table 4 of this Edition; Table 4 of 2000 Edition);

--- Delete the hydraulic test requirements; and add the air tightness test requirements (see 6.6 of this Edition; 5.4.2 of 2000 Edition).

1 Scope

This Standard Specifies the classification, ordering content, size, shape, weight and allowable deviation, technical requirements, test methods, inspection rules, packaging, marking and quality certificates of seamless small diameter stainless steel tubes.

This Standard is applicable to aerospace, electromechanical, instrumentation components, medical needles and other general-purpose seamless stainless-steel tubes with a nominal outer diameter no greater than 6mm (hereinafter referred to as steel tubes).

2 Normative References

The following documents are essential to the application of this document. For the dated documents, only the versions with the dates indicated are applicable to this document; for the undated documents, only the latest version (including all the amendments) are applicable to this document.

GB/T 222 Permissible Tolerances for Chemical Composition of Steel Products

GB/T 223.11 Iron, Steel and Alloy - Determination of Chromium Content - Visual Titration or Potentiometric Titration Method

GB/T 223.25 Methods for Chemical Analysis of Iron, Steel and Alloy - The Dimethylglyoxime Gravimetric Method for the Determination of Nickel Content

GB/T 223.28 Methods for Chemical Analysis of Iron, Steel and Alloy - The alpha-Benzoinoxime Gravimetric Method for the Determination of Molybdenum Content

GB/T 223.59 Iron, Steel and Alloy - Determination of Phosphorus Content - Bismuth Phosphomolybdate Blue Spectrophotometric Method and Antimony Phosphomolybdate Blue Spectrophotometric Method

GB/T 223.60 Methods for Chemical Analysis of Iron, Steel and Alloy - The Perchloric Acid Dehydration Gravimetric Method for the Determination of Silicon Content

GB/T 223.63 Methods for Chemical Analysis of Iron, Steel and Alloy - The Sodium (Potassium) Periodate Photometric Method for the Determination of Manganese

4 Ordering Content

The contract or order that orders products according to this Standard shall include the following:

a) Number of this standard;

b) Product name;

c) Steel designation;

d) Dimension specifications;

e) Ordering quantity (total weight or total length or the number of pieces);

f) Delivery status;

g) Special requirements.

5 Size, Shape, Weight and Allowable Deviation

6 Technical Requirements

7 Test Methods

7.1 Sampling for the analysis of chemical composition of steel tubes shall be conducted according to the rules of GB/T 20066. The chemical composition analysis is usually carried out according to GB/T 11170, GB/T 20123 or other general methods. When arbitrating, it should be carried out according to the provisions of GB/T 223.11, GB/T 223.25, GB/T 223.28, GB/T 223.59, GB/T 223.60, GB/T 223.63, GB/T 223.84, GB/T 223.85, GB/T 223.86.

7.2 The dimensions of steel tubes shall be measured one by one with measuring tools that meet the accuracy requirements.

7.3 The outer surface of the steel pipe shall be visually inspected one by one under sufficient lighting conditions; at least 2 steel tubes are randomly selected from each batch; and take about 50mm tube sections at any position of the sampled steel tube; and the inner surface is visually inspected under sufficient lighting conditions, If necessary, visually inspect the tube section after dissection.

7.4 The sampling methods and test methods of other inspection items of steel tubes shall comply with the provisions in Table 5. […]