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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 1348-2009 Spheroidal graphite cast iron and the following main technical changes have been made with respect to GB/T 1348-2009:
——the scope is modified (see Clause 1; Clause 1 of Edition 2009);
——some terms and definitions are added (see Sub-clauses 3.1, 3.2, 3.5 to 3.9);
——the low-temperature impact property indexes of spheroidal graphite cast iron are modified (see Table 2, Table 4 of Edition 2009);
——three designations of spheroidal graphite cast iron are added (see Table 1);
——the tensile properties of solid solution strengthened ferritic spheroidal graphite east iron are added (see Table 3);
——the side-by-side cast samples are added (see Sub-clause 8.2.4).
This standard has been redrafted and modified adoption of ISO 1083: 2018 Spheroidal graphite cast irons - Classification.
This standard is changed from ISO 1083: 2018 in structure; the comparison table for clause numbers in this standard and those in ISO 1083: 2018 are listed in Annex A.
Compared with ISO 1083:2018, this standard has the following technical differences and causes:
——the adjustments of technical deviations are made for the normative references in this standard so as to adapt to the technical conditions of China. The adjustments are mainly reflected in Clause 2 "Normative reference", which are detailed as follows:
ISO 148-1 is replaced by GB/T 229, which is modified in relation to the corresponding international standard;
ISO 945-1 is replaced by GB/T 9441, which is modified in relation to the corresponding international standard;
ISO 6506-1 is replaced by GB/T 231.1, which is modified in relation to the corresponding international standard;
ISO 6892-1 is replaced by GB/T 228.1, which is identical to the corresponding international standard;
ISO/TR 15931 is replaced by GB/T 5612, which is modified in relation to the corresponding international standard;
the reference for GB/T 223.3, GB/T 223.4, GB/T 223.60, GB/T 223.72, GB/T 223.83, GB/T 223.86, GB/T 5611, GB/T 5677, GB/T 6060.1, GB/T 6414, GB/T 9443, GB/T 9444, GB/T 11351, GB/T 24234 and GB/T 34904 is added.
——for convenience of use, the repeated terms in GB/T 5611 are deleted and the term "solid solution strengthened" is added (see Sub-clause 3.7);
——the technical conditions for appearance quality of castings are added in order to meet the structure of product standards (see Sub-clauses 7.4~7.8).
——the test method for casting quality and performance are added in order to meet the requirements of product test and ensure the accuracy of test (see Sub-clauses 9.3~9.10).
——the casting markings, accompanying documents, storage and transportation requirements are added to meet the needs of users (see Clauses 11 and 12).
This standard was proposed by and is under the jurisdiction of National Technical Committee on Foundry of Standardization Administration of China (SAC/TC 54).
The previous editions of this standard are as follows:
——GB/T 1348-1978, GB/T 1348-1988 and GB/T 1348-2009.
Spheroidal graphite iron castings
1 Scope
This standard specifies the designation, order information, production method and chemical composition, technical requirements, test pieces preparation, test methods, inspection rules, marking and quality certificates, rust prevention, packaging and storage of spheroidal graphite cast irons.
This standard is applicable to ordinary or low alloy ferritic to pearlitic spheroidal graphite east iron and solid solution strengthened ferritic spheroidal graphite east iron in sand moulds or moulds of comparable thermal behaviour. This standard may also be applicable to the spheroidal graphite cast iron produced by special casting methods.
This standard is not applicable to spheroidal graphite cast irons used for pipes, fittings, accessories and joints;
This standard is not applicable to austenitic spheroidal cast irons;
This standard is not applicable to ausferritic cast irons (austempered spheroidal graphite cast irons).
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 223.3 Methods for chemical analysis of iron, steel and alloy - The diantipyrylmethane phosphomolybdate gravimetric method for the determination of phosphorus content
GB/T 223.4 Alloyed steel - Determination of manganese content - Potentiometric or visual titration 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 223.72 Iron steel and alloy - Determination of sulfur content - Gravimetric method
GB/T 223.83 Steel and iron - Determination of high sulfur content - Infrared absorption method after combustion in an induction furnace (GB/T 223.83-2009, ISO 13902:1997, IDT)
GB/T 223.86 Steel and iron - Determination of total carbon content - Infrared absorption method after combustion in an induction furnace (GB/T 223.86-2009, ISO 9556:1989, IDT)
GB/T 228.1 Metallic materials - Tensile testing - Part 1 : Method of test at room temperature (GB/T 228.1-2010, ISO 6892-1:2009, IDT)
GB/T 229 Metallic materials - Charpy pendulum impact test method (GB/T 229-2007, ISO 148-1:2006, MOD)
GB/T 231.1 Metallic materials - Brinell hardness test - Part 1: Test method (GB/T 231.1-2018, ISO 6506-1:2014, MOD)
GB/T 231.2 Metallic materials - Brinell hardness test - Part 2: Verification and calibration of testing machines (GB/T 231.2-2012, ISO 6506-2:2005, MOD)
GB/T 231.3 Metallic materials - Brinell hardness test - Part 3: Calibration of reference blocks (GB/T 231.3-2012, ISO 6506-3:2005, MOD)
GB/T 5611 Foundry terminology
GB/T 5612 Code for representing cast iron (GB/T 5612-2008, ISO/TR 115931:2004, MOD)
GB/T 5677 Castings - Radiographic testing (GB/T 5677-2018, ISO 4993:2015, MOD)
GB/T 6060.1 Surface roughness comparison specimen - Part 1: Casting surface
GB/T 6414 Castings - System of dimensional tolerances, geometrical tolerancing and machining allowances (GB/T 6414-2017, ISO 8062-3: 2007, MOD)
GB/T 944 Metallographic test for spheroidal graphite cast iron (GB/T 9441-2009, ISO 945-1: 2008, MOD)
GB/T 9443 Steel and iron castings - Liquid penetrant inspection (GB/T 9443-2007, ISO 4987:1992, IDT)
GB/T 9444 Magnetic particle testing for steel castings (GB/T 9444-2007, ISO 4986:1992, IDT)
GB/T 11351 Mass tolerances for castings
GB/T 24234 Cast iron - Determination of multi-element contents - Spark discharge atomic emission spectrometric method (Routine method)
GB/T 34904 Spheroidal graphite iron castings - Ultrasonic testing
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 5611 and the following apply.
3.1
spheroidal graphite cast iron
cast material, iron, carbon and silicon-based, the carbon being present mainly in the form of spheroidal graphite particles
3.2
ferritic to pearlitic spheroidal graphite east iron
spheroidal graphite cast iron with a matrix containing ferrite or pearlite or a combination of both
3.3
graphite spheroidizing treatment
spheroidizing treatment
process that brings the liquid iron into contact with a substance to produce graphite in the predominantly spheroidal (nodular) form during solidification
3.4
relevant wall thickness
section of the casting to which the determined mechanical properties shall apply
3.5
cast sample
quantity of material cast to represent the cast material, including separately cast sample, side-by-side cast sample and cast-on sample
3.6
side-by-side cast sample
sample cast in the mould alongside the casting, with a joint running system
3.7
solid solution strengthened
phenomena that solute atoms dissolve into the metal matrix to form a solid solution, which increases the strength and hardness of the metal
3.8
solid solution strengthened ferritic spheroidal graphite east iron
spheroidal graphite cast iron with a matrix mainly consisting of ferrite, solution strengthened by increasing the amount of silicon
3.9
test unit; inspection lot; test batch
number of pieces or the tonnage of castings to be accepted or rejected together, on the basis of the tests carried out on test pieces
4 Designation of spheroidal graphite cast iron
4.1 The spheroidal graphite cast iron, including ferritic to pearlitic spheroidal graphite east iron and solid solution strengthened ferritic spheroidal graphite east iron, shall be designated in accordance with GB/T 5612.
a) see table 1 for the 14 designations which are defined according to the mechanical properties of ferritic to pearlitic spheroidal graphite east iron.
b) see table 3 for the 3 designations which are defined according to the mechanical properties of solid solution strengthened ferritic spheroidal graphite east iron.
4.2 The designation of casting material is determined by measuring the mechanical properties of the following test pieces:
——separately cast test pieces: cut and processed on the separately cast sample.
——side-by-side cast test pieces: cut and processed on the side-by-side cast sample.
——cast-on test pieces: cut and processed on the cast-on sample.
——casting test pieces: cut and processed on the casting sample.
The designation of casting material is defined according to the mechanical properties measured from the test pieces.
5 Order information
5.1 The following information shall be supplied by the purchaser:
a) the complete designation of the material;
b) any special requirements (including the relevant wall thickness, where necessary) that shall be agreed upon between the manufacturer and the purchaser.
5.2 All ordering requirements shall be agreed upon between the manufacturer and the purchaser by the time of acceptance of the order.
6 Production method and chemical composition
6.1 The production method and chemical composition of spheroidal graphite cast iron shall be determined by the manufacturer. The chemical composition of spheroidal graphite cast iron shall not be the basis for acceptance of castings.
6.2 For ferritic to pearlitic spheroidal graphite east iron, the mechanical property grade is determined depending on the proportion of ferritie and pearlite. Generally, the proportion of ferrite and pearlite is adjusted by adjusting the alloy content or by heat treatment.
6.3 The mechanical properties of solid solution strengthened ferritic spheroidal graphite east iron depend on the solid solution strengthened of ferritic matrix, which mainly depends on the silicon content. See Annex B for the chemical composition and physical properties of solid solution strengthened ferritic spheroidal graphite east iron.
7 Technical requirements
7.1 General
7.1.1 The property values in this standard apply to spheroidal graphite cast irons cast in sand moulds or moulds of comparable thermal behaviour. Subject to the agreement between the manufacturer and the purchaser in the order, they can apply to castings obtained by alternative methods.
7.1.2 The material designation is based on the minimum mechanical properties obtained in cast samples with a thickness or diameter of 25 mm. The designation is irrespective of the type of cast sample.
7.2 Ferritic to pearlitic spheroidal graphite east iron
7.2.1 Test pieces machined from cast samples
7.2.1.1 Tensile properties
The tensile properties of ferritic to pearlitic spheroidal graphite cast iron test pieces shall be as specified in Table 1.
Table 1 Tensile properties of ferritic to pearlitic spheroidal graphite cast iron test pieces
Material designation Relevant wall thickness t
mm Proof strength Rp0.2
(min.)
MPa Tensile strength, Rm
(min.)
MPa Elongation after fracture Aa
(min.)
%
QT450-10 t≤30 310 450 100
30
Contents of GB/T 1348-2019
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Designation of spheroidal graphite cast iron
5 Order information
6 Production method and chemical composition
7 Technical requirements
8 Sampling
9 Test methods
10 Inspection rules
11 Marking and quality certificate
12 Rust prevention, packaging and storage
Annex A (Informative) Structural changes of this standard with respect to ISO 1083:
Annex B (Informative) Additional information on solid solution strengthened ferritic spheroidal graphite cast irons
Annex C (Informative) Guidance values for mechanical properties measured on test pieces machined from samples cut from the castings
Annex D (Normative) Relationship between the elongation values obtained when using test pieces with Lo = 5d and Lo = 4d
Annex E (Informative) Classification as a function of hardness
Annex F (Informative) Nodularity
Annex G (Informative) Mechanical and physical properties of spheroidal graphite cast iron materials
Annex H (Informative) Sectioning procedure for cast samples
Annex I (Informative) Cross-references of grade designations from this document to other standard grades of spheroidal graphite cast irons
