GB/T 46219-2025Corrosion-resistant alloy U-bent tubes (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents". Drafting.

Please note that some content in this document may involve patents. The issuing organization of this document assumes no responsibility for identifying patents.

This document was proposed by the China Iron and Steel Association.

This document is under the jurisdiction of the National Steel Standardization Technical Committee (SAC/TC183).

This document was drafted by: Zhejiang Jiuli Special Materials Technology Co., Ltd., Iron & Steel Research Institute Co., Ltd., and Jiangsu Yinhuan Precision Steel Pipe Co., Ltd.

Limited Liability Company, Jiangsu Wujin Stainless Steel Co., Ltd., Steel Research Institute Nake Testing Technology Co., Ltd., Metallurgical Industry Information and Standardization Research Institute, Jiangsu Changbao Plassen Steel Pipe Co., Ltd., Shanxi Taigang Stainless Steel Pipe Co., Ltd., Changshu Huaxin Special Steel Co., Ltd., Zhejiang Yongshang Special Materials Co., Ltd. Limited Company.

The main drafters of this document are: Cao Ping, Luo Xia, Song Zhigang, Zhuang Jianxin, Zhou Zhibin, Luo Jing, Gao Pei, Wang Bowen, Sima Qiongjie, and Deng Zhijian.

Wang Lin, Yan Shengzhi, Feng Han, Yan Chengming, Shao Xinzhong, Shen Xuekang, Xu Huan, Li Jun, Liu Heng, Bao Nan, Wang Hongbin, Zhang Guangjin.

Corrosion-resistant alloy U-tube

1 Scope

This document provides the classification and designation of corrosion-resistant alloy U-tubes, and specifies the ordering details, manufacturing process, technical requirements, inspection rules, and packaging.

Packaging, markings, and quality certificates describe the corresponding test methods.

This document applies to nickel-based plastics with a nominal outer diameter not exceeding 38 mm, a wall thickness not exceeding 3.0 mm, and a bending radius not exceeding 2000 mm.

Iron-nickel based and other corrosion-resistant alloy U-shaped tubes (hereinafter referred to as U-shaped tubes).

2 Normative references

GB/T 222

GB/T 223

GB/T 228.1

GB/T 228.2

GB/T 241

GB/T 242

GB/T 246

GB/T 2102

GB/T 2975

GB/T 5777-2019

GB/T 6394

GB/T 7735-2016

GB/T 10561-2023

GB/T 10610

GB/T 15260

GB/T 20066

GB/T 20123

GB/T 30062

GB/T 38939

3 Terms and Definitions

The terms and definitions defined in GB/T 30062 apply to this document.

4 Classification and Codes

4.1 U-shaped tubes are classified into the following two categories according to their delivery condition.

a) Heat-treated U-shaped tube UH;

b) Cold-rolled (drawn) U-shaped tube UC.

4.2 The symbols and corresponding explanations used in this document are shown in Table 1.

Table 1 Symbols and Explanations Symbol Unit Explanation D mm Nominal outer diameter Dmax mm Maximum outer diameter Dmin mm Minimum outer diameter S mm Nominal wall thickness Smin mm minimum wall thickness R mm is the bending radius, the straight-line distance between the center of the bend and the centerline of the bend area.

b mm Straight pipe section spacing, vertical distance between the inner sides of two straight pipe sections at the bend tangent point.

lambda mm Straight pipe section spacing deviation T mm. Minimum wall thickness in the bend region; minimum wall thickness at the outer arch of the bend region.

Ov % Out-of-roundness of the bend, referring to the ratio of the difference between the maximum and minimum outer diameters at any cross-section of the bend to the nominal outer diameter. Lu mm U-shaped tube length L mm Straight pipe section length deltaL mm represents the difference in length between two straight pipe sections, |L1-L2 | deltaL1/deltaL2 mm is the deviation in straight pipe section length; it is the difference between the lengths of the two straight pipe sections L1/L2 and the nominal straight pipe section length L.

P mm Flatness, the maximum vertical distance between various parts of the bend and the horizontal plane.

5 Order details

A contract or order placed in accordance with this document shall include at least the following.

a) This document number;

b) Product Name;

c) Trademark or Uniform Numerical Code;

d) Smelting methods;

e) Delivery status;

f) Dimensions (outer diameter x wall thickness, in millimeters);

g) Product drawings (including bending radius and straight pipe section length);

h) Quantity ordered (total length, total number of pieces, or total weight);

i) Hydraulic test pressure;

j) Special requirements (such as penetration).

6 Manufacturing process

1 H08800 NS1101 960°C~1060°C, rapid cooling

2 H08810 NS1102 1100°C~1180°C, rapid cooling

3 H01103 NS1103 980°C~1050°C, rapid cooling

4 H01401 NS1401 1000°C~1050°C, rapid cooling

5 H08825 NS1402 960°C~1080°C, rapid cooling

6 H06600 NS3102 980°C~1060°C, rapid cooling

7 H06690 NS3105 1000°C~1100°C, rapid cooling

8 H06625 NS3306 1050°C~1150°C, rapid cooling

Table 3 Recommended stress-relieving heat treatment regimes Serial Number, Unified Numerical Code, Grade, Recommended Stress-Relieving Heat Treatment System (a) 1 H08800 NS1101 900°C~1050°C, holding time not less than 5s, rapid cooling after holding.

2 H08810 NS1102 900°C~1050°C, holding time not less than 5s, rapid cooling after holding.

3 H01103 NS1103 900°C~1050°C, holding time not less than 5s, rapid cooling after holding.

4 H01401 NS1401 900°C~1050°C, holding time not less than 5s, rapid cooling after holding.

5 H08825 NS1402 950°C~1050°C, holding time not less than 5s, rapid cooling after holding.

6 H06600 NS3102 950°C~1050°C, holding time not less than 5s, rapid cooling after holding.

7 H06690 NS3105 950°C~1050°C, holding time not less than 5s, rapid cooling after holding.

8 H06625 NS3306 950°C~1050°C, holding time not less than 5s, rapid cooling after holding.

During the stress-relieving heat treatment process, a protective gas should be passed through the inner surface of the pipe, and the purity of the gas should not be less than 99.99%.

7 Technical Requirements