GB 9948-2013 English PDF (GB9948-2013)

Delivery: 2 working-hours manually (Sales@ChineseStandard.net)
Need delivered in 3-second? USA-Site: GB 9948-2013
Get Quotation: Click GB 9948-2013 (Self-service in 1-minute)
Historical versions (Master-website): GB 9948-2013
Preview True-PDF (Reload/Scroll-down if blank)

GB 9948-2013: [GB/T 9948-2013] Seamless steel tubes for petroleum cracking
GB 9948-2013
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.140.75
H 48
Replacing GB 9948-2006
Seamless steel tubes for petroleum cracking
ISSUED ON. SEPTEMBER 18, 2013
IMPLEMENTED ON. JULY 01, 2014
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine of the People's Republic of China;
Standardization Administration of the People's Republic of
China.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative references ... 5
3 Classification, code ... 8
4 Ordering contents ... 9
5 Dimension, shape, weight and permissible deviation ... 9
6 Technical requirements ... 13
7 Test methods ... 23
8 Inspection rules ... 24
9 Packaging, marking and quality certificate ... 24
Annex A (informative) Comparison table of similar steel grades ... 25
Annex B (normative) Supplementary technical requirements for cracking
resistance of steel tubes of high-quality carbon structural steel used in H2S-
containing environments ... 26
Foreword
In this Standard, 5.5, 6.1. 1, 6.1.2, 6.1.3, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9,
6.10.1, 6. 11, 7, 8, 9 are mandatory, and others are recommended.
This Standard was drafted according to the rules given in GB/T 1.1-2009.
This Standard replaces GB 9948-2006 “Seamless steel tubes for petroleum
cracking”. Compared with GB 9948-2006, in addition to the editorial
amendments, the main technical changes of this Standard are as follows.
- ADD the delivery method by minimum wall thickness;
- MODIFY the permissible deviation of the dimension of steel tubes;
- MODIFY the grade and chemical component of steel; ADD the steel grade
12Cr1Mo, 12Cr2Mo, 12Cr1MoV, 12Cr9Mo-I, 12Cr9Mo-NT, 07Cr19Ni11Ti,
022Cr17Ni12Mo2;
- MODIFY the manufacturing methods and requirements for tube billets;
- MODIFY the mechanical properties of steel tubes;
- MODIFY the heat treatment system of steel tubes;
- MODIFY the requirements for non-destructive testing.
- ADD the inter-granular corrosion test;
- ADD the supplementary technical requirements for steel tubes of high-
quality carbon structural steel used in H2S-containing environments.
This Standard was drafted by referring ASTM A335/A335M-10 “Specifications
of Ferric Alloy Steel Seamless Steel Tubes in High Temperature” (English
edition), ASTM A213/A213M-10 “Specification of Ferric and Austenitic Alloy
Steel Seamless Steel Tubes Used for Boiler, Superheater and Heat Exchanger”
(English edition) and EN 10216-2.2002 “Delivery Technical Conditions of
Seamless Steel Tube Used for Pressure - Part 2. Regulated Non-alloy Steel
and Alloy Steel with High-temperature Performance” (English edition).
This Standard was proposed by China Iron and Steel Industry Association.
This Standard shall be under the jurisdiction of National Technical Committee
on Steel of Standardization Administration of China (SAC/TC 183).
Drafting organizations of this Standard. Chengdu Steel and Vanadium Co., Ltd.
of Panzhihua Iron and Steel Group, An Steel Co., Ltd., Hunan Hualing Steel
Seamless steel tubes for petroleum cracking
1 Scope
This Standard specifies the classification, code, dimension, shape, weight,
technical requirements, test methods, inspection rules, packaging, marking and
quality certificate of seamless steel tubes for petroleum cracking.
This Standard is applied to the seamless steel tubes used for petrochemical
furnace tubes, heat exchanger tubes and pressure 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 222 Permissible tolerances for chemical composition of steel products
GB/T 223.3 Methods for chemical analysis of iron, steel and alloy - The
diantipyrylmethane phosphomolybdate gravimetric method for the
determination of phosphorus content
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 223.12 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 223.13 Methods for chemical analysis of iron, steel and alloy - The
ammonium ferrous sulfate titration method for the determination of vanadium
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 223.62 Methods for chemical analysis of iron, steel and alloy - The
butyl acetate extraction photometric method for the determination of
phosphorus content
GB/T 223.63 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 alloyed - 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 223.69 Iron steel and alloy - Determination of carbon contents - Gas-
volumetric method after combustion in the pipe furnace
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 223.74 Methods for chemical analysis of iron, steel and alloy - The
combustion gravimetric/gas-volumetric method for the determination of
combined carbon content
GB/T 226 Etch test for macrostructure and defect of steels
GB/T 228.1 Metallic materials - Tensile testing - Part 1. Method of test at
room temperature
GB/T 229 Metallic materials - Charpy pendulum impact test method
GB/T 231.1 Metallic materials - Brinell hardness test - Part 1. Test method
GB/T 232 Metallic materials - Bend test
GB/T 241 Metal materials - Tube - Hydrostatic pressure test
GB/T 242 Metal materials - Tube - Drift-expending test
GB/T 246 Metal materials - Tube - Flattening test
GB/T 1979 Standard diagrams for macrostructure and defect of structural
steels
a) Hot rolled (extruded, expanded) steel tube W-H;
b) Cold drawn (rolled) steel tube W-C.
4 Ordering contents
The contract or order for ordering the steel tube according to this Standard shall
include the following contents.
a) Standard number;
b) Product name;
c) Grade of steel;
d) Ordered quantity (total weight or total length);
e) Dimension specification (outside diameter × wall thickness, in mm);
f) Delivery status;
g) Special requirements.
5 Dimension, shape, weight and permissible deviation
5.1 Outside diameter and wall thickness
5.1.1 Unless otherwise specified in the contract, the steel tube shall be
delivered by the nominal outside diameter (D) and nominal wall thickness (S).
According to the requirements of demander, by consultation of the supplier and
demander, the steel tube may be delivered by the nominal outside diameter (D)
and minimum wall thickness (Smin).
5.1.2 The nominal outside diameter and wall thickness of steel tube shall
comply with the specifications of GB/T 17395. According to the requirements of
demander, by consultation of supplier and demander, it may supply the steel
tube with other outside diameters and wall thicknesses.
5.1.3 For the steel tube delivered by the nominal outside diameter and nominal
wall thickness, the permissible deviation of outside diameter and wall thickness
of the steel tube shall comply with the specifications of Table 1.
5.1.4 For the steel tube delivered by the nominal outside diameter and minimum
wall thickness, the permissible deviation of outside diameter of the steel tube
shall comply with the specifications of Table 1, and the permissible deviation of
wall thickness shall comply with the specifications of Table 2.
5.3.1 The curvature per meter of steel tube shall comply with the following
specifications.
a) When S ≤ 15 mm, the curvature shall not be more than 1.5 mm/m;
b) When S >15 mm ~ 30 mm, the curvature shall not be more than 2.0 mm/m;
c) When S > 30 mm or D ≥ 351 mm, the curvature shall not be more than
3.0 mm/m.
5.3.2 For the steel tube with an outside diameter of not less than 127 mm, the
curvature in total length shall not be more than 0.10 % of the length of the steel
tube.
5.3.3 According to the requirements of demander, by consultation of supplier
and demander, and indicated in the contract, other specifications may be used
for the curvature per meter and curvature in total length of steel tubes.
5.4 Out-of-roundness and unevenness in wall thickness
According to the requirements of demander, by consultation of the supplier and
demander, and indicated in the contract, the out-of-roundness and unevenness
in wall thickness of steel tubes shall not exceed 80 % of the tolerance of outside
diameter and wall thickness.
5.5 End shape
The end faces at two ends of the steel tube shall be vertical with the axis of the
steel tube, and the burrs of incision shall be removed.
5.6 Weight
5.6 .1 Delivery weight
When the steel tube is delivered according to the nominal outside diameter and
nominal wall thickness, the steel tube can be delivered either according to the
actual weight or according to the theoretical weight.
When the steel tube is delivered according to the nominal outside diameter and
nominal wall thickness, the steel tube can be delivered according to the actual
weight. By consultation of supplier and demander, and indicated in the contract,
the steel tube can also be delivered according to the theoretical weight.
5.6.2 Calculation of theoretical weight
The calculation of theoretical weight shall comply with the specifications of
GB/T 17395. The density of high-quality carbon structural steel and alloy
structural steel is calculated as 7.85 kg/dm3; the density of stainless (heat
D - the nominal outside diameter of the steel tube, in millimeters (mm);
α - the deformation coefficient of unit length, which is 0.09 for 10 steel, 0.08
for 20 steel and alloy structural steel, and 0.09 for stainless (heat resistant)
steel; when S/D ≥ 0.125, α value is reduced by 0.01.
When the specimen is flattened to the distance H between two plates, the
specimen is not allowed to have cracks or slits.
6.6.2 Bending test
6.6.2.1 Steel tubes with an outside diameter of more than 400 m or a wall
thickness of more than 40 mm may be subjected to the bending test instead of
the flattening test. A group of bending tests shall include a forward bending (the
specimen surface near the outside surface of the steel tube is deformed due to
the tension) and a reverse bending (the specimen surface near the inside
surface of the steel tube is deformed due to the tension).
The bending core diameter of the bending test is 25 mm, and the specimen
shall be bended 180° at room temperature.
After bending test, the bending tension surface and side surface of the
specimen are not allowed to have visible cracks or slits.
6.6.2.2 The specimen for bending test shall be cut off along the transverse
direction of the steel tube, and the preparation of specimen shall comply with
the specifications of GB/T 232. When cutting off the specimen, the forward
bending specimen shall be close to the outside surface as possible, and the
reverse bending specimen shall be close to the inside surface as possible. The
bending tension deformed surface of the specimen is not allowed to have
obvious scars and other defects.
The cross-sectional dimension of processed specimen is 12.5 mm × 12.5 mm
or 25 mm × 12.5 mm (width × thickness); four corners on the cross-section shall
be rounded off, and the fillet radius is not more than 1.6 mm; the length of
specimen shall not be more than 150 mm.
6.6.3 Flaring test
Steel tubes of high-quality carbon structural steel and stainless (heat resistant)
steel with an outside diameter of not more than 76 mm and a wall thickness of
not more than 8 mm shall be subjected to the flaring test. The flaring test shall
be implemented at the room temperature, and the top core taper is 60 °. The
flaring rate of outside diameter of the specimen after flaring shall comply with
the specifications of Table 7. The specimen after flaring is not allowed to have
cracks or slits.
the maximum depth is 0.2 mm;
b) Hot rolled (extruded, expanded) steel tubes. not more than 5 % of wall
thickness, and the maximum depth is 0.4 mm.
Other local defects that do not exceed the permissible negative deviation of
wall thickness are allowed to exist.
6.10 Non-destructive testing
6.10.2 Steel tubes shall be subjected to the ultrasonic testing one by one
according to the specifications of GB/T 5777-2008. The vertical carving groove
depth grade of comparison specimen tube for ultrasonic testing is L2.5 for hot
rolled (extruded, expanded) steel tubes; L2 for cold drawn (rolled) steel tubes.
When the steel tubes are delivered by the minimum wall thickness, the carving
groove depth of comparison specimen tube shall be calculated by the average
wall thickness of steel tubes.
6.10.2 When the ratio of the wall thickness and outside diameter of steel tubes
(S/D) is greater than 0.2, unless otherwise specified in the contract, the depth
of the artificial detect of inside wall of steel tubes shall be in accordance with
the specifications of C.1 of Annex C in GB/T 5777-2008.
6.10.3 According to the requirements of demander, by consultation of supplier
and demander, and indicated in the contract, it may add other non-destructive <...