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GB/T 9439-2023 PDF in English


GB/T 9439-2023 (GB/T9439-2023, GBT 9439-2023, GBT9439-2023)
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GB/T 9439-2023: PDF in English (GBT 9439-2023)

GB/T 9439-2023
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.080.10
CCS J 31
Replacing GB/T 9439-2010
Grey iron castings
(ISO 185:2020, Gray iron castings - Classification, NEQ)
ISSUED ON: SEPTEMBER 07, 2023
IMPLEMENTED ON: SEPTEMBER 07, 2023
Issued by: State Administration for Market Regulation.
Standardization Administration of PRC.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative references ... 5
3 Terms and definitions ... 6
4 Designations of gray iron castings ... 7
5 Production methods and chemical composition ... 9
6 Technical requirements ... 10
7 Specimen preparation ... 12
8 Test methods ... 17
9 Inspection rules ... 21
10 Marking, quality certificate, surface protection, packaging, storage and
transportation ... 23
Appendix A (Informative) Mechanical and physical properties of gray iron casting . 24
Appendix B (Informative) Relationship between hardness and tensile strength of gray
iron casting ... 26
Appendix C (Informative) Relationship between the body tensile strength, hardness and
section thickness of gray iron castings ... 29
Appendix D (Informative) Comparison of designations of gray iron castings between
GB/T 9439 and other standards ... 33
References ... 34
Grey iron castings
1 Scope
This document stipulates the designations, production methods and chemical
composition, technical requirements, specimen preparation, test methods, inspection
rules and markings, quality certificates, protection, packaging, storage and
transportation of gray iron casting.
This document is applicable to ordinary gray iron castings, which are cast in sand molds
or molds with thermal conductivity equivalent to that of sand molds. Gray iron castings
which are cast in other molds can be used with reference to it.
2 Normative references
The contents of the following documents constitute essential provisions of this
document through normative references in the text. Among them, for dated reference
documents, only the version corresponding to the date applies to this document; for
undated reference documents, the latest version (including all amendments) applies to
this document.
GB/T 223.3 Methods for chemical analysis of iron, steel and alloy - The diantipyryl
methane phosphomolybdate gravimetric method for the determination of
phosphorus content
GB/T 223.4 Methods for chemical analysis of iron, steel and alloy - The volumetric
method for determination of manganese content by ammonium nitrate oxidation
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 223.72 Methods for chemical analysis of iron, steel and alloy - The alumina
chromatographic separation-barium sulfate gravimetric method for the
determination of sulphur content
GB/T 223.86 Steel and iron - Determination of total carbon content - Infrared
absorption method after combustion in an induction furnace
GB/T 228.1 Metallic materials - Tensile testing - Part 1: Method of test at room
temperature
GB/T 231.1 Metallic materials - Brinell hardness test - Part 1: Test method
GB/T 5611 Foundry terminology
GB/T 5612 Code for representing cast iron
GB/T 5677 Castings - Radiographic testing
GB/T 6060.1 Surface roughness comparison specimen - Part 1: Casting surface
GB/T 6414 Castings - Dimensional tolerances and geometrical tolerances and
machining allowances
GB/T 7216 Metallographic test for grey cast iron
GB/T 9443 Steel and iron castings - Liquid penetrant inspection
GB/T 9444 Steel and iron castings - Magnetic particle inspection
GB/T 11351 Mass tolerances of casting
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 24234 Cast iron - Determination of multi-element contents - Spark discharge
atomic emission spectrometric method (Routine method)
GB/T 38441 Pig iron and cast - Determination of chromium, copper, magnesium,
manganese, molybdenum, nickel, phosphorus, tin, titanium, vanadium and silicon
content - Inductively coupled plasma atomic emission spectrometric method
3 Terms and definitions
The terms and definitions defined in GB/T 5611, as well as the following terms and
definitions, apply to this document.
3.1
Relevant wall thickness
The thickness of the casting section, which represents the mechanical properties of
the casting material.
3.2
Side-by-side cast sample
The test samples which are placed side by side with the castings, in the same mold
using the same pouring system.
of the buyer. The chemical components shall be tested at the frequency and quantity
agreed upon by both the supplier and the buyer.
5.3 Unless otherwise specified, castings are delivered as cast.
6 Technical requirements
6.1 Mechanical properties
6.1.1 Tensile strength
6.1.1.1 The tensile strength value of the tensile specimen shall comply with the
requirements in Table 1. The mechanical properties and physical properties of single-
cast samples are as shown in Appendix A.
6.1.1.2 The tensile strength in Table 1 is related to the relevant wall thickness. Usually
ϕ30 mm single-cast sample is used to test the tensile strength.
6.1.1.3 The relationship between the tensile strength and Brinell hardness of gray iron
casting is as shown in Appendix B.
6.1.1.4 If the acceptance items are not clearly specified in the order agreement, the
supplier shall use tensile strength as the main basis for acceptance.
6.1.2 Tensile strength of casting body
6.1.2.1 If tensile specimens are cut out and processed from the casting body, the supplier
and the buyer shall agree on:
- Sampling location;
- The minimum tensile strength value or allowable range value of the bulk specimen.
Note 1: The physical performance values of castings cannot be unified, because they are closely
related to factors such as the complexity of the casting, the wall thickness of the casting, the
cooling rate.
Note 2: The tensile properties of casting body specimens are not only affected by material
properties, but also by defects in the sampling location.
6.1.2.2 The relationship between the tensile strength, Brinell hardness and wall
thickness of the casting body is shown in Appendix C. The expected value of the tensile
strength of the casting body is shown in Table C.1.
6.1.3 Hardness
6.1.3.1 Gray iron casting, which is classified according to hardness, is mainly applicable
to gray iron casting parts, which have cutting performance or wear resistance as the
main evaluation index. The hardness value of gray iron castings shall comply with the
requirements in Table 2.
6.1.3.2 Castings with main wall thickness t > 80 mm are not classified according to
hardness.
6.1.3.3 Unless otherwise specified, HBW represents the Brinell hardness, which is
measured under the test condition of 10/3000.
6.1.3.4 If hardness is used as an acceptance item, the supplier and the buyer shall agree
on the location of the relevant wall thickness and hardness testing; clearly specify it in
the order agreement. Hardness can also be tested on the specimen. Figure C.2 gives the
relationship between the average hardness and the relevant wall thickness in simple
shapes.
6.2 Metallographic structure
6.2.1 The graphite form of gray iron castings is mainly A-type graphite, wherein the A-
type graphite accounts for more than 90%. The total amount of carbide and phosphorus
eutectic in the matrix structure shall be less than 1%.
6.2.2 When the purchaser has clear requirements on the matrix structure and graphite
shape, quantity, distribution size, grade, phosphorus eutectic content, carbide content in
the metallographic structure, the purchaser's technical requirements shall be met.
6.3 Machining allowances, dimensions, dimensional tolerances, geometric shapes,
geometric tolerances
If the buyer has no special requirements, the machining allowance, dimensional
tolerance, geometric tolerance of castings shall be selected according to the provisions
of GB/T 6414.
6.4 Weight tolerance
If the buyer has no special requirements, the weight tolerance of castings shall be
selected according to the provisions of GB/T 11351.
6.5 Surface quality
6.5.1 If the buyer has no special requirements, the surface roughness value of the casting
shall be within the range specified in GB/T 6060.1.
6.5.2 The castings shall be cleaned; the excess parts shall be trimmed; the residue of the
pouring riser, core bone, sticky sand, inner cavity residues shall be removed. The
allowable pouring and riser residues, draped seams, flying burr residues, internal cavity
cleanliness, etc. of castings shall comply with the purchaser's drawings, technical
7.3.2 Detection frequency and quantity
The sampling frequency of specimens representing casting materials shall be consistent
with the supplier's quality control requirements, or shall be agreed upon by both the
supplier and the buyer.
7.3.3 Single-cast sample
7.3.3.1 Single-cast samples are prepared according to Figure 1; the test samples shall
be cast vertically. The test samples and castings shall be poured from the same batch of
molten iron; the test samples shall be poured at the end of the batch of molten iron.
7.3.3.2 The single-cast sample shall be cast in a mold with a similar thermal
conductivity to the casting it represents. Three or more test samples can be poured into
the same mold at the same time. The minimum sand consumption between the test
samples shall be greater than 40 mm.
7.3.3.3 The unpacking sand-out temperature of single-cast samples shall be lower than
500 °C. After negotiation and agreement between the supplier and the buyer, if the
castings are shaken out when the temperature is higher than 500 °C, the single-cast
samples can also be unpacked and shaken out when the temperature is higher than
500 °C.
7.3.3.4 If the casting requires heat treatment, the test samples shall be treated in the
same furnace as the casting it represents; when the casting is subjected to stress-
relieving aging treatment, the test samples may not be treated.
7.3.3.5 The length L of the test sample is determined according to the length of the test
sample and the clamping device, as shown in Figure 1. The length L of the test sample
depends on the type A or B test sample (see 8.1.3), as well as the length of the clamping
section. The dimensions of the specimens processed with single-cast samples are as
shown in Table 3.
7.3.3.6 Test samples of other sizes or produced using other casting processes shall be
agreed upon by both the supplier and the buyer. Figure C.1 shows the relationship
between the minimum tensile strength and the main wall thickness of castings of simple
shapes.
7.3.4 Side-by-side cast samples
7.3.4.1 Side-by-side cast samples represent castings of the same batch that are cast in
the same batch and have similar relevant wall thicknesses. The test samples shall be
cast at the end of the same batch of castings.
7.3.4.2 The dimensions of the side-by-side cast samples are as shown in Figure 1.
7.3.5 Attached cast samples
7.3.5.1 The attached cast sample represents the attached casting and the same batch of
castings with similar relevant wall thickness. The casting with the attached cast samples
shall be poured at the end of the same batch of castings.
7.3.5.2 The shape and size of the attached cast samples are as shown in Figure 2 or
Figure 3. The length L of the attached cast sample shall be determined, based on the
length of the cast sample and the length of the clamping end.
7.3.5.3 Two sets of dimensions are given in Figures 2 and 3, wherein the larger cast
sample dimensions are given in parentheses. The small-sized attached cast sample is
suitable for castings, which have a wall thickness less than 100 mm; the large-sized
attached cast sample is used for castings, which have a wall thickness not less than 100
mm.
7.3.5.4 The type, size and cast-in position of the attached-cast sample shall be agreed
between the supplier and the buyer, OR by the supplier itself.
7.3.5.5 When the relevant wall thickness is greater than 20 mm and the mass is greater
than 200 kg, an attached cast sample should be used.
7.3.5.6 If the casting requires heat treatment, the attached cast sample shall be cut after
the casting is heat treated.
7.3.6 Casting bulk specimen
7.3.6.1 If necessary, both the supplier and the purchaser can specify the performance of
the specified position of the casting; prepare specimens at the specified locations and
test the mechanical properties of the specimens.
7.3.6.2 The size of the bulk specimen shall be selected according to Table 3, OR it shall
be agreed upon by both the supplier and the buyer through negotiation.
7.3.6.3 If the purchaser does not specify, the sampling position of the bulk specimen
shall be determined by the supplier itself.
7.4 Hardness test block
7.4.1 The hardness can be tested on a hardness test block at a certain position of the
attached cast sample. The shape and size of the hardness test block are as shown in
Figure 4. The position of the hardness test block on the attached cast sample shall be
agreed upon by the supplier and the buyer.
7.4.2 The hardness test block is used for castings which have a wall thickness of not
less than 20 mm. The test block is cut from the casting; after the cut surface is ground,
the Brinell hardness value is measured on the smoothed surface.
7.4.3 If the casting requires heat treatment, the hardness test block shall be cut after the
taken for testing below 1.5 mm from the surface of the castings.
8.5 Non-destructive testing
8.5.1 Magnetic particle testing shall be carried out in accordance with the provisions of
GB/T 9444.
8.5.2 Penetration testing shall be carried out in accordance with the provisions of GB/T
9443.
8.5.3 Radiographic testing shall be carried out in accordance with the provisions of
GB/T 5677.
8.6 Casting dimensions, dimensional tolerances, geometric tolerances
8.6.1 The geometric shape, dimensional inspection points, machining reference points
of castings shall be marked by the purchaser.
8.6.2 The geometric tolerances and dimensional tolerances of castings shall be tested
using corresponding precision testing tools, gauge blocks, templates or markings.
8.6.3 Samples and trial production castings shall be submitted with full-size inspection
reports; the inspection quantity shall be agreed upon by both the supplier and the buyer.
Castings supplied in mass production shall submit critical dimension (or important
dimension) inspection reports on a batch-by-batch basis; the testing frequency and
quantity shall be agreed upon by both the supplier and the buyer.
8.7 Defect detection
8.7.1 Detection of surface and internal defects of castings:
a) Surface defects of castings shall be detected visually, magnetic particle inspection
or penetrant inspection; auxiliary inspection methods may also be used;
b) Internal defects of castings can be detected by X-ray.
8.7.2 The appearance defects of castings shall be visually inspected piece by piece.
However, for the inspection of internal defects of castings with complex geometric
shapes and inner cavity shapes, random inspections can be carried out according to the
inspection frequency, inspection quantity, inspection method agreed upon by both the
supplier and the buyer.
8.8 Optional test methods
Upon agreement between the supplier and the buyer, equivalent test methods can also
be used to measure tensile strength, Brinell hardness, metallographic structure.
9 Inspection rules
9.1 Group-batching
Casting inspection batches are divided as follows.
a) Castings produced by the same mold and poured from the same molten iron in the
same furnace constitute a sampling batch.
b) Castings poured from the same molten iron package constitute a sampling batch.
c) Castings with a total mass of 2000 kg form a sampling batch.
d) If the mass of a single piece is greater than 2000 kg, it can be a separate sampling
batch.
e) When a large amount of molten iron is continuously melted, the maximum mass
of each sampling batch shall not exceed the mass of the castings poured within 2
hours.
f) If a designation of molten iron has a large melting capacity, it adopts system-
controlled melting technology and strict production process control, meanwhile
it can carry out certain forms of rapid pre-furnace inspection and quality control
on a package (furnace) basis, such as white opening testing, spectral composition
analysis, thermal analysis, composition adjustment, etc., THEN, upon agreement
between the supplier and the buyer, several batches of castings can also be used
to constitute a sampling batch.
g) During continuous production, such as when the charge, process conditions, or
chemical composition change, all castings poured with continuously molten iron
during this period, no matter how short the time interval, are regarded as a
sampling batch.
9.2 Chemical composition analysis
Chemical composition shall be tested batch by batch, based on sampling batches.
9.3 Tensile strength test
The specimens used for mechanical property testing shall be taken from the test sample
(block) or the casting body; a tensile test shall be conducted for each sampling batch.
9.4 Hardness test
The hardness test can be carried out on the casting body or on the tensile specimen or
hardness test block. Each sampling batch shall be tested once for hardness.
10 Marking, quality certificate, surface protection,
packaging, storage and transportation
10.1 Casting marking
10.1.1 If the size of the casting allows, the supplier's code, trademark, part code,
production date, production sequence number, etc. shall be marked on the non-
machined surface.
10.1.2 If the buyer does not have clear requirements for the location, size (font size,
font height, convex and concave) and method of the marking, the supplier shall
determine by itself.
10.1.3 When it is not possible to mark the castings, the marking may be printed on the
label attached to each batch of castings.
10.2 Quality certificate
Castings shipped from the factory shall be accompanied by an inspection certificate or
quality certificate. The quality certificate shall at least include but not be limited to the
following:
a) Name of supplier;
b) Casting name, casting code (part number);
c) The casting drawing number, material designation, testing report of the test items
agreed upon by both the supplier and the buyer, the corresponding production
date and batch;
d) Other documents required by the supply agreement.
10.3 Surface protection, packaging, storage and transportation
10.3.1 Castings shall be protected after passing the inspection.
10.3.2 The surface protection, packaging, storage and transportation of castings shall
comply with the provisions of the order agreement.
......
 
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.