GB/T 14985-2007 PDF in English
GB/T 14985-2007 (GB/T14985-2007, GBT 14985-2007, GBT14985-2007)
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| GB/T 14985-2007 | English | 160 |
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General rules of dimensions, shape, surface, quality, testing method and inspection for expansion alloys
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| GB/T 14985-1994 | English | 439 |
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General rules of dimensions, shape, surface quality, test mothod and inspection for expansion alloys
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Standards related to (historical): GB/T 14985-2007
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GB/T 14985-2007: PDF in English (GBT 14985-2007) GB/T 14985-2007
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.140.99
H 58
Replacing GB/T 14985-1994
General rules of dimensions, shape, surface, quality, testing
method and inspection for expansion alloys
ISSUED ON: AUGUST 14, 2007
IMPLEMENTED ON: MARCH 01, 2008
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 Order content ... 7
4 Dimensions, shapes and allowable deviations ... 8
5 Surface quality ... 12
6 Testing methods ... 12
7 Inspection rules ... 13
8 Packaging, marks and quality certificate ... 14
Annex A (normative) Inspection method for expansion alloy phase transformation .. 15
General rules of dimensions, shape, surface quality, testing
method and inspection for expansion alloys
1 Scope
This Standard specifies the dimensions, shape and allowable deviation, surface quality,
testing methods, inspection rules, packaging, marks and quality certificates for
expansion alloys.
This Standard applies to expansion alloys with a certain average linear expansion
coefficient within a certain temperature range.
2 Normative references
The provisions in following documents become the provisions of this Standard through
reference in this Standard. For dated references, the subsequent amendments (excluding
corrigendum) or revisions do not apply to this Standard, however, parties who reach an
agreement based on this Standard are encouraged to study if the latest versions of these
documents are applicable. For undated references, the latest edition of the referenced
document 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 daintily
methane phosphomolybdate gravimetric method for the determination of
phosphorus content
GB/T 223.4, Iron, steel and alloy - 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 223.9, 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 223.17, Methods for chemical analysis of iron, steel and alloy - The
diantipyrylmethane photometric method for the determination of titanium content
GB/T 223.78, Methods for chemical analysis of iron, steel and alloy - Curcumin
spectrophotometric method for the determination of boron content
GB/T 226, Test method for macrostructure and defect of steel by etching
GB/T 228, Metallic materials - Tensile testing at ambient temperature (GB/T 228-
2002, eqv ISO 6892:1998)
GB/T 342-1997, Dimension shape mass and tolerance for cold-drawn round square
and hexagonal steel wires
GB/T 702-2004, Hot-rolled round and square steel bars - Dimension, Shape, weight
and tolerance
GB/T 908-1987, Forged round and square steels dimension, shape, weight and
tolerance
GB/T 1979, Standard diagrams for macrostructure and defect of structural steels
GB/T 2975, Steel and steel products - Location and preparation of samples and test
pieces for mechanical testing (GB/T 2975-1998, eqv ISO 377:1997)
GB/T 3207-1988, Bright steel
GB/T 4339, Test methods for thermal expansion characteristic parameters of
metallic materials
GB/T 4340.1, Metallic materials - Vickers hardness test - Part 1: Test method
GB/T 6394, Determination of estimating the average grain size of metal
GB/T 5778-1986, Determination of hermeticity of expansion alloys
GB/T 10561, Steel - Determination of content of nonmetallic inclusions -
Micrographic method using standards diagrams
GB/T 13297, General rules of packaging, marking and quality certification for
precision alloys
GB/T 20066, Steel and iron - Sampling and preparation of samples for the
determination of chemical composition (GB/T 20066-2006, ISO 14284:1998, IDT)
3 Order content
The contract or order for ordering according to this Standard shall include the
followings:
a) Reference to this Standard;
b) Product name;
c) Designation or unified numerical code;
d) Weight (or quantity) of the delivery;
e) Size and shape;
f) Processing method;
g) Delivery state and performance;
h) Special requirements.
4 Dimensions, shapes and allowable deviations
4.1 Cold drawn (pulled) wires
4.1.1 Dimension and allowable deviation
The diameter of cold drawn (pulled) wire is: 0.10 mm ~ 7.00 mm. The allowable
deviation of its diameter shall comply with the precision requirements in Table 2 or
Table 3 in GB/T 342-1997. The accuracy grade should be specified in the contract.
When not specified, it is provided with grade 10 accuracy.
4.1.2 Shape
The shape of the cold-drawn (pulled) wire should comply with the relevant regulations
of GB/T 342-1997.
4.2 Cold rolled (drawn) pipes
4.2.1 Dimension and allowable deviation
4.2.1.1 Outer diameter and allowable deviation for inner-outer diameters, wall
thickness
The outer diameter and allowable deviation for inner and outer diameters, wall
thickness of cold rolled (drawn) seamless pipes shall comply with the regulations of
Table 1. Other specifications and size tolerances are negotiated between the supplier
and the buyer.
4.6.2.1 The diameter of hot rolled bars is 6.0 mm ~ 12.0 mm. The round steel shall be
delivered in coils. When the buyer requires delivery in straight strips, it shall be
specified in the contract.
4.6.2.2 The curvature of each meter of length of hot rolled products delivered in straight
strips shall not be greater than 2.5 mm. The total curvature is not greater than 0.25% of
the total length.
5 Surface quality
5.1 Cold rolled (pulled, drawn, polished) material
The surface of cold rolled (pulled, drawn, polished) materials should be smooth.
Defects such as microcracks, delamination, folds, scars, rust, scratches, oxidized colors,
and pitting are not allowed.
5.2 Hot forged (rolled) material
Defects such as cracks, folds, scales, heavy skin, depressions, and ears are not allowed
on the surface of hot forged (rolled) materials. But the above defects allow cleaning.
The cleaning depth should not exceed half of the tolerance.
6 Testing methods
The testing methods for the performance inspection of each batch of alloys shall be
carried out in accordance with the provisions in Table 5.
7 Inspection rules
7.1 Inspection and acceptance
The inspection and acceptance of finished products shall be carried out by the quality
and technical supervision department of the supplier.
7.2 Batching rules
Finished products should be submitted in batches for inspection and acceptance. Each
batch consists of alloy materials with the same alloy designation, the same furnace (tank)
number, the same processing method, the same size, the same delivery state, and the
same heat treatment system.
7.3 Sampling quantity and sampling site
The sampling quantity and sampling site of each batch of alloy materials shall comply
with the requirements in Table 5.
7.4 Reinspection and judgement rules
7.4.1 If the inspection results of the expansion coefficient are unqualified, double the
number of samples should be taken for reinspection. Even if one sample is unqualified
in the reinspection results, this furnace of alloys shall be rejected.
7.4.2 If the grain size and hardness test results are unqualified, double the number of
samples should be taken for reinspection. Even if one specimen is unqualified in the
reinspection results, this batch of alloys shall be rejected. But piece-by-piece inspection
is allowed. When the grain size and hardness pass the inspection at the same time, the
products can be delivered.
7.4.3 When the alloy phase transformation test is unqualified, reinspection is not
allowed. However, it is allowed to re-roll (forge) alloy materials with smaller
dimensions and resubmit them for inspection as a new batch (except for 4J28 alloys).
For the phase transformation inspection of 4J29, 4J32, 4J34, and 4J40 alloys, it is
allowed to replace the inspection results of alloy materials of smaller specifications with
larger specifications of the same furnace number.
7.4.4 When the user requests to test the airtightness of alloy materials, each batch of
alloy materials shall be managed according to A and B heads. The airtightness test
specimen is taken from the A head of the first branch. If the inspection result is
unqualified, take another sample from the B head of the second branch for reinspection.
If the reinspection result is still unqualified, then this batch of alloys shall be rejected.
7.4.5 If the dimension, shape and surface quality are unqualified, it will be judged as
unqualified product.
7.4.6 If the results of other inspections are unqualified, double the number of specimens
should be taken for reinspection of the unqualified items. If the reinspection results are
still unqualified, then this batch of alloys shall be rejected.
8 Packaging, marks and quality certificate
The packaging, marks and quality certificate of finished alloy materials shall comply
with the relevant provisions of GB/T 13297.
A.4 Instruments and reagents
A.4.1 Thermos bottle.
A.4.2 Acetone (or absolute ethanol).
A.4.3 Carbon dioxide (dry ice).
A.4.4 Low temperature thermometer.
A.5 Test
A.5.1 Freezing of specimens
Pour an appropriate amount of acetone (or absolute ethanol) into the thermos. Put dry
ice in the bottle and stir to bring the temperature down to the desired temperature. Then
put the polished or corroded specimen into the thermos. Re-temper to the specified
temperature. After freezing, take out the specimen. Warm it up to room temperature,
rinse and dry it for inspection. The freezing temperature and freezing time of the alloy
shall comply with Table A.3 regulations.
A.5.2 Inspection and assessment of results
A.5.2.1 Take the specimen that has been subjected to freezing treatment. Carefully
observe whether there is γ→α martensitic transformation on the entire polished surface
under a magnifying glass of 100 ~ 400 times. Fe-Cr (4J28) alloy is examined for
acicular martensite at room temperature.
A.5.2.2 At room temperature, the martensite is observed after corrosion. Its needles are
black. Frozen martensitic needles are light in color and mostly distributed in groups.
When the number is large, it is often distributed in series along the processing direction.
Sometimes stripe scratches are visually observed on the polished surface. This is
because the γ→α martensitic transformation is an embossing phenomenon caused by
volume expansion. Figure A.2 and Figure A.3 are specimens without martensitic
transformation and with martensitic transformation, respectively.
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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