GB/T 38681-2020 in English

VALID

Seamless corrosion resistant alloy pipes and tubes for industrial furnace

Issued on:2020-03-31
Implemented on:2020-10-01
File Format:PDF
Delivery:Via email within 1~3 business days

Price(USD)： $160.00
$156.00

Standard No:	GB/T 38681-2020
Document status:	VALID
Title in English:	Seamless corrosion resistant alloy pipes and tubes for industrial furnace
Title in Chinese:	工业炉用耐蚀合金无缝管
Language:	English
File Format:	Electronic (PDF)
Delivery:	Via email within 1~3 business days
Issued on:	2020-03-31
Implemented on:	2020-10-01
ICS Classification:	77.140.75-Steels pipes and tubes for specific use
Chinese Classification:	H59-Other special alloys
Professional Classification:	GB-National Standard
Related Keywords:	iron-nickel-based/nickel-based corrosion-resistant alloy seamless pipes resistant alloy pipes intergranular corrosion test seamless corrosion alloy grade
Related Topics:	industrial furnace gb t 15260 Alloy tube seamless pipe GBT38681 GB/T 38681-2020 Corrosion resistance Corrosion Resistant Alloy Corrosion-resistant alloy composite oil pipe execution suture industry

《GB/T 38681-2020工业炉用耐蚀合金无缝管》由TC183（全国钢标准化技术委员会）归口，TC183SC10（全国钢标准化技术委员会特殊合金分会）执行，主管部门为中国钢铁工业协会。

Introduction

Analysis of the core content of the standard

Scope of application

This standard is applicable to iron-nickel-based/nickel-based corrosion-resistant alloy seamless pipes with a nominal outer diameter of ≤406mm and a wall thickness of ≤60mm, mainly used in:

Petroleum refining industrial furnaces
Chemical production equipment
Polysilicon production equipment

Comparison of key technical requirements

Project	Hot-extruded pipe (WH)	Cold-rolled (drawn) pipe (WC)	Test method
Outer diameter tolerance	±1%D or ±0.75%D	±0.75%D or ±0.5%D	GB/T 17395
Wall thickness tolerance	+15%/-10%S	+12%/-10%S	Micrometer measurement
Bending degree	≤2.0mm/m	≤1.5mm/m	Platform rolling test
Flattening test	H≤(1+η)S/(η+S/D),η=0.09		GB/T 246

Key indicators of material performance

Mechanical properties of typical grades

NS1101: Rm≥520MPa, Rp0.2≥205MPa, A≥30%
NS3306: Rm≥690MPa(solid solution), Rp0.2≥275MPa
NS1402: Rm≥585MPa, Rp0.2≥240MPa

Note: All specimens must be sampled according to GB/T 2975, and room temperature tensile test shall comply with GB/T 228.1

Key points for the implementation of the standard

Key links in quality control

Metallurgy control: Electric arc furnace + external refining or electroslag remelting process must be adopted
Non-destructive testing:
- Ultrasonic testing shall not be lower than U2 level (GB/T 5777)
- Eddy current testing can replace water pressure test (GB/T 7735)
Surface quality: Straight channel depth of cold-rolled tube ≤4% wall thickness and ≤0.3mm

Precautions for ordering

The contract must clearly state: alloy grade, size specifications, manufacturing method (WH/WC), accuracy grade (PA/PC), special requirements (such as intergranular corrosion test, etc.)

Technical development background

This standard is formulated for petrochemical industry furnace tubes in extreme working conditions of high temperature, high pressure + corrosive media. Compared with traditional stainless steel tubes: