GB/T 37610-2019 English PDF (GBT37610-2019)

This Standard specifies order content, size, appearance, technical requirements, test methods, inspection rules, packaging, marks and quality certificate of corrosion-resistant alloy small diameter precision seamless tubes. This Standard is applicable to corrosion-resistant alloy cold-rolled (drawn) small diameter precision seamless tubes such as nickel based, iron nickel based, pure nickel and nickel copper of which nominal outer diameter is 3mm~30mm, and wall thickness is 0.3mm~3.0mm.

GB/T 37610-2019
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.140.99;77.140.75
H 59
Corrosion-resistant alloy small diameter precision
seamless tubes
ISSUED ON: JUNE 04, 2019
IMPLEMENTED ON: MAY 01, 2020
Issued by: State Administration for Market Regulation;
Standardization Administration of the People's Republic of
China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Order content ... 6
4 Size, appearance ... 7
5 Technical requirements ... 8
6 Test methods ... 15
7 Inspection rules ... 16
8 Packaging, marks and quality certificate ... 17
Foreword
This Standard was drafted in accordance with the rules given in GB/T 1.1-2009. This Standard was proposed by China Iron and Steel Association.
This Standard shall be under the jurisdiction of National Technical Committee on Steel of Standardization Administration of China (SAC/TC 183).
The drafting organizations of this Standard: Zhejiang Jiuli Special Material Technology Co., Ltd., Jiangsu Wujin Stainless Co., Ltd., Metallurgical Industry Information Standards Institute, Yongxing Special Stainless-Steel Co., Ltd., Baosteel Special Steel Co., Ltd., Shanxi Taigang Stainless Steel Pipe Co., Ltd., Zhejiang Yongshang Special Material Co., Ltd., Shanghai Yilang Alloy Material Co., Ltd., Harbin Electric Group (Qinhuangdao) Heavy Equipment Co., Ltd., Pangang Group Jiangyou Great Wall Special Steel Co., Ltd., Huzhou Sanjing Cryogenic Equipment Co., Ltd., Fushun Special Steel Co., Ltd.
Main drafters of this Standard: Cai Zhigang, Li Zhengzhou, Yan Chengming, Ding Jinxian, Wang Jianyong, Ma Mingjuan, Cheng Yiming, FangDewei, Fu
Huaqing, Ye Jinhui, Fang Tie, Jiang Wentao, Wu Bo, Cao Lihong, Cao Ping, Wu Minghua, Li Peng, Huang Wei.
Corrosion-resistant alloy small diameter precision
seamless tubes
1 Scope
This Standard specifies order content, size, appearance, technical
requirements, test methods, inspection rules, packaging, marks and quality certificate of corrosion-resistant alloy small diameter precision seamless tubes. This Standard is applicable to corrosion-resistant alloy cold-rolled (drawn) small diameter precision seamless tubes such as nickel based, iron nickel based, pure nickel and nickel copper of which nominal outer diameter is 3mm~30mm, and wall thickness is 0.3mm~3.0mm (hereinafter referred to as alloy tubes). 2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 223.4, Alloyed steel - Determination of manganese content -
Potentiometric or visual titration method
GB/T 223.5, Steel and iron - Determination of acid-soluble silicon and total silicon content - Reduced molybdosilicate spectrophotometric method
GB/T 223.11, Iron, Steel and Alloy - Determination of Chromium Content - Visual Titration or Potentiometric Titration Method
GB/T 223.14, Methods for Chemical Analysis of Iron, Steel and Alloy - The N-Benzoy-N-Phenylhydroxylamine Extraction Photometric Method for the
Determination of Vanadium Content
GB/T 223.17, Methods for chemical analysis of iron, steel and alloy - The diantipyryl methane photometric method for the determination of titanium content
GB/T 223.18, Methods for chemical analysis of iron, steel and alloy - The sodium thiosulfate separation iodometric method for the determination of copper content
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 223.26, Iron, steel and alloy - Determination of molybdenum content - The thiocyanate spectrophotometric method
GB/T 223.38, Methods for chemical analysis of iron, steel and alloy - The anion-exchange separation-gravimetric method for the determination of
niobium content
GB/T 223.43, Iron, steel and alloy - Determination of tungsten content - Gravimetric method and spectrophotometric method
GB/T 223.62, Methods for chemical analysis of iron, steel and alloy - The butyl acetate extraction photometric method for the determination of
phosphorus content
GB/T 223.65, Steel, iron and alloy - Determination of cobalt content - Flame atomic absorption spectrometric method
GB/T 223.70, Iron, steel and alloy - Determination of iron contents - O- phenanthroline spectrophotometric method
GB/T 223.79, Iron and steel - Determination of multi - element contents - X - ray fluorescence spectrometry (Routine method)
GB/T 223.81, Iron, steel and alloy - Determination of total aluminum and total boron contents - Microwave digestion - inductively coupled plasma mass
spectrometric method
GB/T 228.1, Metallic materials - Tensile testing - Part 1: Method of test at room temperature
GB/T 228.2, Metallic materials - Tensile testing - Part 2: Method of test at elevated temperature
GB/T 241, Metal Materials - Tube - Hydrostatic pressure test
GB/T 242, Metal Materials - Tube - Drift-expending test
GB/T 246, Metallic materials - Tube - Flattening test
GB/T 2102, Acceptance, packing, marking and quality certification of steel pipe
GB/T 5777-2008, Seamless Steel Pipe and Tubing Methods for Ultrasonic
Testing
GB/T 6394, Metal - Methods for estimating the average grain size
GB/T 7735-2016, Automated eddy current testing of seamless and welded
(except submerged arc-welded) steel tubes for detection of imperfections GB/T 10561-2005, Steel - Determination of Content of Nonmetallic
Inclusions - Micrographic Method Using Standards Diagrams
GB/T 11170, Stainless steel - Determination of multi-element contents - Spark discharge atomic emission spectrometric method (Routine method)
GB/T 15007, Designations of corrosion-resistant alloy
GB/T 15260-2016, Standard Test Method for Intergranular Corrosion of
Nickel Alloys by Corrosion of Metals and Alloys
GB/T 20066, Steel and Iron - Sampling and Preparation of Samples for the Determination of Chemical Composition
GB/T 20123, Steel and iron - Determination of total carbon and sulfur content Infrared absorption method after combustion in an induction furnace (routine method)
GB/T 20125, Low-alloy steel - Determination of multi-element contents - Inductively coupled plasma atomic emission spectrometric method
YB/T 4395, Steel Determination of molybdenum, niobium and tungsten
contents. Inductively coupled plasma atomic emission spectrometric method YS/T 325.2, Methods for chemical analysis of nickel-copper alloy - Part 2: Determination of copper content - Electrolysis weight method
3 Order content
Contract or order for alloy tubes according to this Standard shall at least contain following information:
a) reference to this Standard;
b) product name;
c) alloy designation;
d) delivery state;
e) specification (outer diameter × wall thickness × length, in millimeters); f) delivery quantity (total length, total number of pieces or total weight); g) production method;
h) special requirements.
4 Size, appearance
4.1 Outer diameter and wall thickness
4.1.1 General size of alloy tubes: nominal outer diameter is 3.0mm~30mm, and nominal wall thickness is 0.3mm~3.0mm.
4.1.2 Unless otherwise specified in contract, alloy tubes are delivered according to nominal outer diameter (D) and nominal wall thickness (S). Allowable deviations of nominal outer diameter (D) and nominal wall thickness (S) shall comply with provisions on Group I in Table 1. According to purchaser’s
requirements and agreed by supplier and purchaser, allowable deviation of alloy tubes shall be in accordance with requirements for Group II in Table 1. Table 1 -- Allowable deviations of nominal outer diameter and nominal
wall thickness of alloy tubes
mm
4.1.3 According to purchaser’s requirements and agreed by supplier and
purchaser, when alloy tubes are delivered according to minimum wall thickness Smin, allowable deviation of minimum wall thickness Smin shall comply with provisions of Table 2.
Table 2 -- Allowable deviation of minimum wall thickness of alloy tubes Minimum wall thickness Smin Allowable deviation
0.3~3.0
4.1.4 Agreed by supplier and purchaser, alloy tubes of other specifications outside Table 1 and Table 2 can be supplied. Allowable deviations shall be indicated in contract.
Alloy tube size Group I Group II
Nominal outer
diameter D
Nominal wall thickness
4.2 Length
4.2.1 General length
General length of alloy tubes is 1000mm~15000mm. According to purchaser’s requirements, agreed by supplier and purchaser and indicated in contract, alloy tubes of other lengths can be supplied.
4.2.2 Fixed length and multiplied length
Agreed by supplier and purchaser and indicated in contract, alloy tubes of fixed length and multiplied length can be supplied. Fixed length and multiplied length shall be within general length range. Allowable deviation of fixed length is mm. Allowable deviation of multiplied length is mm. Each multiple length shall leave a fracture allowance of 3mm~5mm.
4.3 Degree of curvature
Degree of curvature of alloy tubes shall not exceed 1.5mm/m. Degree of
curvature of full length shall not exceed 0.15% of total length. For alloy tubes of which length is less than 1000mm, degree of curvature shall not exceed 1mm/m. Requirements for other degrees of curvature shall be indicated in contract. 4.4 Un-roundness and uneven wall thickness
Un-roundness and uneven wall thickness of alloy tubes shall not exceed 80% of outer diameter tolerance and wall thickness tolerance, respectively. 4.5 End face shape
End face shapes of both ends of alloy tube shall be perpendicular to axis of alloy tube. There shall be no burrs on tube ends.
5 Technical requirements
5.1 Designation and chemical composition
5.1.1 Designation and chemical composition (smelting analysis) of alloy tubes shall comply with provisions of Table 3.
5.1.2 Allowable deviation of chemical composition of finished alloy tubes shall comply with provisions of GB/T 15007.
Table 3 -- Alloy designation and chemical composition
No
Unified
digital
code
Alloy
designa
tion
Chemical composition (mass fraction)/%
Other
Allowa
nce
Allowa
nce
Allowa
nce
Allowa
nce
Table 3 (continued)
No
Unified
digital
code
Alloy
designa
tion
Chemical composition (mass fraction)/%
Other
Allowa
nce
Allowa
nce
Allowa
nce
Allowa
nce
NOTE: Compositions of P, S of some designations in the table are stricter than GB/T 15007. 5.2 Production method
5.2.1 Smelting method
Alloy shall use electric arc furnace plus outside-furnace refining plus electro- slag re-melting to smelt. It can also use other methods that be able to meet requirements of this Standard to smelt. Smelting method shall be indicated in quality certificate.
5.2.2 Tube production method
5.2.2.1 Alloy ingots for tube production shall be hot-rolled or hot-forged to round bars. On round bars, parts that are equivalent to alloy ingot head and tail shall be completely cut off.
5.2.2.2 Round bars shall use hot extrusion method to open blank. Cold-rolling of alloy tubes shall use cold-rolling (drawing) to produce.
5.3 Delivery state
5.3.1 Alloy tubes shall be delivered in state of protective atmosphere heat treatment or vacuum heat treatment. See Table 4 for recommended heat
treatment system.
5.3.2 According to purchaser’s requirements, alloy tubes can be delivered in cold-rolling (drawing) state.
5.4 Mechanical properties
5.4.1 Tensile at room temperature
Longitudinal tensile properties at room temperature of alloy tubes in delivery state shall comply with provisions of Table 4. Indicators of mechanical properties of alloy tubes delivered in cold-rolling (drawing) state shall be determined by supplier and purchaser via negotiation and indicated in contract. Table 4 -- Recommended heat treatment system and mechanical
properties
Table 4 (continued)
5.4.2 Hardness
Alloy tubes used for instrumentation system shall be subject to hardness test. Test methods and requirements shall be determined by supplier and purchaser through negotiation.
No. Unified digital
code
Alloy
designation Recommended heat treatment system
Tensile
strength
Rm/MPa
Specified
plastic
extension
strength
Rp0.2/MPa
Elongation
after break
A/%
Instant cooling
Instant cooling
Instant cooling
Instant cooling
Instant cooling
Instant cooling
Instant cooling
Instant cooling
Instant cooling
Instant cooling
Instant cooling
Instant cooling
Annealing, 870°C~980°C, instant cooling
Quench annealing, 980°C~1150°C, instant cooling
Quench annealing, 940°C~1100°C, instant cooling
Aging treatment, 718°C~760°C, cooling with
furnace
No. Unified digital
code
Alloy
designation
Recommended heat treatment
system
Tensile
strength
Rm/MPa
Specified
plastic
extension
strength
Rp0.2/MPa
Elongation
after break
A/%
Annealing, 815°C~925°C, instant cooling
Stress relief, 480°C~705°C, instant cooling
Annealing,760°C~870°C, instant cooling
Stress relief, 480°C~705°C, instant cooling
Annealing,870°C~980°C, instant cooling
Stress relief, 540°C~565°C, instant cooling
a Steel level 1 uses annealing. Steel level 2 uses quench annealing.
b If NS4301 alloy tubes are delivered in aging treatment state, mechanical properties of quench annealing state are only used as reference.
c Insulation time shall not be less than 3h.
5.5 Grain size
Average grain size of NS1102, NS1104 alloy tubes shall be level 5 or more coarse. Average grain size of NS1103, NS1402, and NS3105 alloy tubes shall be level 5 and finer. Grain size of NS4301 alloy tube shall be level 3 or finer. Agreed by supplier and purchaser and indicated in contract, requirements for other grain sizes can be specified.
5.6 Non-metallic inclusions
Inspection of non-metallic inclusions shall be performed on tube blank that is used to produce tube. Acceptance levels shall comply with provisions of Table 4.
Table 5 -- Acceptance levels for non-metallic inclusions
Types of non-metallic
inclusions
A B C D E
Level, not greater than
Fine series 1.0 1.5 1.5 1.5 1.5 Coarse series 1.0 1.5 1.5 1.5
Sum of levels of A, B, C, D categories shall not exceed level 4.0.
5.7 Process performance
5.7.1 Flaring test
Alloy tubes shall be subject to flaring test. Top core taper of flaring test is 30° (outer diameter is not more than 10mm) or 60° (outer diameter is more than 10mm). Flaring rate of outer diameter of flared sample shall not be less than 30% of nominal outer diameter. Flared sample shall not have cracks. Alloy tubes that are delivered in cold-rolling (drawing), that are delivered in stress relief heat treatment state and aging treatment state, have no requirements for flaring test.
5.7.2 Flattening test
5.7.2.1 Alloy tubes shall be subject to flattening test. After sample is flattened, distance between two plates H is calculated according to formula (1)；
Where,
H - Distance between two plates after being flattened, in millimeters (mm); α - Deformation coefficient of unit length;
S - Nominal wall thickness of alloy tube, in millimeters (mm);
D - Nominal outer diameter of alloy tube, in millimeters (mm).
5.7.2.2 When sample is flattened to distance between two plates H, there shall be no cracks on surface outside sample. Slight cracks on sample corner shall not be basis for determination. For alloy tubes that are delivered in cold-rolling (drawing) state, stress relief heat treatment state and aging treatment state, there are no requirements for flattening test.
5.8 Ultrasonic testing
5.8.1 For alloy tubes of which nominal outer diameter is not less than 6mm, it shall perform ultrasonic testing on inner and outer surfaces. Acceptance level shall comply with provisions on level L2 in GB/T 5777-2008. For alloy tubes of which nominal outer diameter is less than 6mm, it shall perform ultrasonic testing for last intermediate straight tube of 6mm or before 6mm. Acceptance level shall comply with provisions on level L2 in GB/T 5777-2008.
5.8.2 According to purchaser’s requirements, agreed by supplier and purchaser and indicated in contract, ultrasonic testing can use other acceptance levels. 5.9 Eddy current testing
Alloy tubes shall be subject to eddy current testing. Acceptance level shall comply with provisions on level E1H in GB/T 7735-2016. Agreed by supplier and purchaser and indicated in contract, eddy current testing can use other acceptance levels.
5.10 Surface quality
5.10.1 There shall be no defects such as cracks, folds, rolls, separation and crusting on inner and outer surfaces of alloy tubes. These defects shall be cleared. Surface of alloy tube at clearing shall be smooth, without edges and corners. Actual wall thickness at clearing shall not be less than minimum value allowed by wall thickness.
5.10.2 Other slight surface scratches, straightening stamps, and cold rolling waves that do not exceed allowable deviation are allowed. On outer surface of alloy tube, allowable scratch depth is not greater than 3% of nominal wall thickness or 0.05mm. Take the larger of two.
5.10.3 For tubes used for instrumentation system, outer surface roughness Ra shall not exceed 0.80μm.
5.10.4 Inner and outer surfaces of alloy tubes shall be clean. There shall be no foreign matter such as oil, dust and debris. There shall be no corrosive medium such as residual acid or lye.
5.11 Special requirements
According to purchaser’s requirements, agreed by supplier and purchaser and indicated in contract, it shall perform following inspections to alloy tubes: a) high-temperature tensile test;
b) hydraulic test or underwater airtight test;
c) intergranular corrosion test;
d) other pressure test;
e) delivery in other heat treatment systems;
f) others.
6 Test methods
6.1 Inspection items and test methods of alloy tubes shall comply with
provisions of Table 6.
6.2 Chemical composition analysis of alloy tubes is in accordance with general methods such as GB/T 223.79, GB/T 11170, GB/T 20123, GB/T 20125. But in arbitration, it is in accordance with provisions of GB/T 223.4, GB/T 223.5, GB/T 223.11, GB/T 223.14, GB/T 223.17, GB/T 223.18, GB/T 223.25, GB/T 223.26, GB/T 223.38, GB/T 223.43, GB/T 223.62, GB/T 223.65, GB/T 223.70, GB/T
223.81, YB/T 4395, YS/T 325.2.
6.3 Underwater airtight test medium is compressed air. Test pressure shall be 0.6MPa~0.8MPa. Voltage regulation time shall be no less than 5s.
6.4 Visually inspect inner and outer surface qualities of alloy tubes under full lighting conditions. Use roughness tester to test surface roughness or use roughness comparison test block to perform visual inspection.
6.5 Use measuring tool that meets accuracy requirements to measure size and appearance of alloy tube.
Table 6 -- Inspection items, sampling quantity, sampling methods and
test methods of alloy tubes
No. Inspection item Sampling quantity...