GB/T 33156-2016 English PDF (GB/T33156-2016)

GB/T 33156-2016: Precision Welded Tubes for Gas Spring
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GB/T 33156-2016
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.140.75
H 48
Precision Welded Tubes for Gas Spring
ISSUED ON: OCTOBER 13, 2016
IMPLEMENTED ON: SEPTEMBER 01, 2017
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration of the People's Republic of
China.
Table of Contents
Foreword ... 3 
1 Scope ... 4 
2 Normative references ... 4 
3 Classification, code ... 6 
4 Ordering content ... 7 
5 Size, shape, weight and allowable deviation ... 7 
6 Technical requirements ... 10 
7 Inspection and test methods ... 14 
8 Test rules ... 15 
9 Packaging, marking and quality certificate ... 15 
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 Industry Association.
This Standard shall be under the jurisdiction of National Technical Committee
183 on Iron and Steel of Standardization Administration of China (SAC/TC 183).
The drafting organizations of this Standard: Jiangsu DOM Corporation Limited,
Qingdao Sanhong Precision Instrument Co., Ltd.
The drafters of this Standard: Zhou Feiyao, Pu Chengfu, Bao Yongli, Zhang
Qixu, Yao Zhiqiang, Jiang Xiaojun, Yu Qingwen.
Precision Welded Tubes for Gas Spring
1 Scope
This Standard specifies the classification, code, size, shape, weight and
allowable deviation, technical requirement, inspection and test method,
inspection rule, packaging, marking and quality certificate of precision welded
tubes for gas spring.
This Standard applies to cold-drawn or cold-rolled precision welded tubes for
gas spring (including seat air pressure bars and lifters) in machinery
manufacturing, vehicle manufacturing, and furniture products.
2 Normative references
The following documents are indispensable for the application of this document.
For dated references, only the dated version applies to this document. For
undated references, the latest edition (including all amendments) applies to this
document.
GB/T 222, Permissible tolerances for chemical composition of steel products
GB/T 223.5, Steel and iron. Determination of acid-soluble silicon and total
silicon content. Reduced molybdosilicate spectrophotometric method
GB/T 223.9, Iron, steel and alloy. Determination of aluminium content.
Chrome azurol S photometric method
GB/T 223.11, Iron, steel and alloy. Determination of chromium content. Visual
titration or potentiometric titration method
GB/T 223.12, Methods for chemical analysis of iron, steel and alloy. The
sodium carbonate separation-diphenyl carbazide photometric method for the
determination of chromium content
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 223.16, Methods for chemical analysis of iron, steel and alloy. The
chromotropic acid 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
cupper content
GB/T 223.19, Methods for chemical analysis of iron, steel and alloy. The
neocuproine-chloroform extraction photometric method for the determination
of copper content
GB/T 223.23, Iron, steel and alloy. Determination of nickel content. The
dimethylglyoxime spectrophotometric method
GB/T 223.26, Iron, steel and alloy. Determination of molybdenum content.
The thiocyanate spectrophotometric method
GB/T 223.32, Methods for chemical analysis of iron, steel and alloy. The
hypophosphite reduction-iodometric method for the determination of arsenic
content
GB/T 223.37, Methods for chemical analysis of iron, steel and alloy. The
indophenol blue photometric methods for the determination of nitrogen
content after distillation separation
GB/T 223.40, Iron, steel and alloy. Determination of niobium content by the
sulphochlorophenol S spectrophotometric method
GB/T 223.53, Methods for chemical analysis of iron, steel and alloy. The
flame atomic absorption spectrophotometric method for the determination of
copper content
GB/T 223.58, Methods for chemical analysis of iron, steel and alloy. The
sodium arsenite-sodium nitrite titrimetric method for the determination of
manganese 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 content
GB/T 223.64, Iron, steel and alloy. Determination of manganese content.
Flame atomic absorption spectrometric method
GB/T 223.68, Methods for chemical analysis of iron, steel and alloy The
potassium iodate titration method after combustion in the pipe furnace for the
determination of sulfur content
GB/T 223.71, Methods for chemical analysis of iron, steel and alloy The
gravimetric method after combustion in the pipe furnace for the determination
of carbon content
GB/T 223.72, Iron, steel and alloy - Determination of sulfur content.
Gravimetric method
GB/T 228.1, Metallic materials. Tensile testing - Part 1: Method of test at
room temperature
GB/T 242, Metal materials. Tube. Drift-expending test
GB/T 246, Metal materials. Tube. Flattening test
GB/T 700, Carbon structural steels
GB/T 1031, Surface roughness parameters and their values
GB/T 1591, High strength low alloy structural steels
GB/T 2102, Acceptance, packing, marking and quality certification of steel
pipe
GB/T 2975, Steel and steel products. Location and preparation of samples
and test pieces for mechanical testing
GB/T 4336, Carbon and low-alloy steel. Spark discharge atomic emission
spectrometric method (routine method)
GB/T 7735-2004, Steel tubes. The inspection method on eddy current test
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
3 Classification, code
Steel pipes are divided into five classifications according to the delivery state,
and their classifications and codes are:
a) cold drawing or cold rolling / hard state: +C;
b) cold drawing or cold rolling / soft state: + LC;
c) stress-relief annealing state: +SR;
d) annealing state: +A;
e) normalizing state: +N.
4 Ordering content
The contract or order form that orders steel pipes according to this Standard
shall include the following:
a) number of this Standard;
b) product name:
c) steel grade (quality grade);
d) dimensions;
e) ordering quantity (total weight or total length);
f) delivery state;
g) manufacturing method;
h) special requirements.
5 Size, shape, weight and allowable deviation
5.1 Outer diameter, inner diameter and wall thickness
5.1.1 Steel pipes shall be delivered in nominal outer diameter (D) and nominal
inner diameter (d). When the buyer requests delivery at the nominal outside
diameter and nominal wall thickness (S) OR nominal inner diameter and
nominal wall thickness, it shall be indicated in the contract.
5.1.2 The outer diameter, inner diameter and wall thickness of steel pipes shall
comply with the requirements of Table 1.
According to the requirements of the buyer, if it is negotiated between the
supplier and the buyer, steel pipes of different sizes than those that are listed
in Table 1 may be supplied.
Table 1 -- Size and allowable deviation
in millimeters
Outer diameter
and allowable
deviation
Wall thickness
Inner diameter
Allowable
deviation of
inner diameter
5.1.3 For cold-drawn or cold-rolled (+C, +LC) steel pipes, the allowable
deviation of the outer and inner diameters shall comply with the requirements
of Table 1.
For heat-treated (+SR, +A, +N) steel pipes, the allowable deviation of the outer
and inner diameters shall comply with the requirements of Table 2.
Table 2 -- Allowable deviation of outer diameter and inner diameter of
heat-treated steel pipes
Serial No. Wall thickness / outer diameter (S/D) Allowable deviation
1 S/D ≥ 0.05 As specified in Table 1
2 0.025 ≤ S/D < 0.05 1.5 times the value specified in Table 1
3 S/D < 0.025 2.0 times the value specified in Table 1
5.1.4 The allowable deviation of the wall thickness of the steel pipe is ±6%S.
5.1.5 According to the requirements of the buyer, if it is negotiated between the
buyer and the supplier AND indicated in the contract, steel pipes of the
dimensional allowable deviation other than those that are specified in Table 1
and Table 2 may be supplied.
5.2 Length
5.2.1 Normal length
The normal length of the steel pipe is 3 000 mm ~ 12 000 mm.
5.2.2 Fixed length
According to the requirements of the buyer, if it is negotiated between the buyer
and the supplier AND indicated in the contract, the steel pipe can be delivered
according to the fixed length. The fixed length of the steel pipe shall be within
the normal length; the full-length allowable deviation shall comply with the
following requirements:
a) for the length not more than 5 000 mm, 0 mm ~ 5 mm;
a) for the length more than 5 000 mm, 0 mm ~ 10 mm;
5.2.3 According to the requirements of the buyer, if it is negotiated between the
buyer and the supplier AND indicated in the contract, steel pipes of other
lengths and allowable deviations may be supplied.
5.3 Bending
5.3.1 The full-length bending of the steel pipe shall not exceed 0.1% of the
length of the steel pipe.
5.3.2 According to the requirements of the buyer, if it is negotiated between the
buyer and the supplier AND indicated in the contract, other provisions may be
imposed for the bending per meter and the full-length bending of the steel pipe.
5.4 End shape
The end faces of the steel pipe shall be perpendicular to the axis of the steel
pipe; the burrs of the cut shall be removed.
5.5 Out-of-roundness and uneven wall thickness
The out-of-roundness and uneven wall thickness of the steel pipe shall be no
more than 80% of the outer diameter allowance and the wall thickness
allowance, respectively.
5.6 Delivery weight
Steel pipes can be delivered according to actual weight and the theoretical
weight. When they are delivered according to the theoretical weight, the
theoretical weight per meter of steel pipe is calculated according to Formula (1):
Where:
W -- the weight per unit length of the steel pipe, in kilograms per meter (kg/m);
D -- the nominal outer diameter of the steel pipe, in millimeters (mm);
S -- the nominal wall thickness of the steel pipe, in millimeters (mm);
6 Technical requirements
6.1 Steel grade and chemical composition
6.1.1 The steel grade and chemical composition (melting analysis) shall comply
with the provisions of Q195, Q215, Q235, Q275 in GB/T 700 and Q345 in GB/T
1591.
According to the requirements of the buyer, if it is negotiated between the
supplier and the buyer, steel pipes of other grades can be supplied.
6.1.2 When the buyer requests an analysis of the finished product, it shall be
indicated in the contract; the allowable deviation of chemical composition of the
finished steel pipe shall comply with the provisions of GB/T 222.
6.2 Manufacturing method
6.2.1 Smelting method of steels
The steel shall be a killed steel that is smelted in an electric furnace or an
oxygen converter.
6.2.2 Manufacturing method of steel pipes
Steel pipes shall be manufactured by electric welded pipe blank through cold-
drawing or cold-rolling.
6.3 Delivery state
Steel pipes shall be delivered in any of the states that are listed in Table 3.
Table 3 -- Delivery state
Serial
No. Code Delivery state Note
1 +C Cold drawing or cold rolling / hard
After the final cold drawing or cold rolling, carry
out no heat treatment
2 +LC Cold drawing or cold rolling / soft
After the final heat treatment, carry out
appropriate cold drawing or cold rolling
3 +SR
After cold drawing or
cold rolling, stress-
relief annealing
After the final cold drawing or cold rolling, for the
steel pipes, adopt a controlled atmosphere
furnace for stress-relief annealing
4 +A Annealing
After the final cold drawing or cold rolling, for the
steel pipes, adopt a controlled atmosphere
furnace for annealing
5 +N Normalizing
After the final cold drawing or cold rolling, for the
steel pipes, adopt a controlled atmosphere
furnace for normalizing
6.4 Mechanical property
6.4.1 Tensile mechanical properties
The tensile mechanical properties of the steel pipe shall comply with the
requirements of Table 4.
Table 4 -- Tensile mechanical properties of the steel pipe
6.4.2 According to the requirements of the buyer, if it is negotiated between the
buyer and the supplier AND indicated in the contract, the steel pipe may be
subjected to a hardness test, and the value shall be determined by mutual
agreement.
6.5 Process performance
6.5.1 Flattening
Steel pipes, of a +A and +N state, of which the wall thickness to outer diameter
ratio of less than 15%, shall be subjected to a flattening test. The distance H
between the plates after the sample is flattened is calculated according to
Formula (2):
Where:
Grade
Rank
Tensile
strength R
MPa
Elongation
after break A
Elongation