GB/T 9439-2023 Grey iron castings
1 Scope
This Document specifies the designation, production method and chemical composition, technical requirements, test pieces preparation, test methods, inspection rules, marking and quality certificates, protection, packaging and transportation of grey cast irons.
This Document is applicable to common grey iron castings with sand mold or a mould of comparable thermal behavior, and may be used as reference for grey iron castings with other molds.
2 Normative references
The following documents contain requirements which, through reference in this text, constitute provisions 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 diantipyryl methane 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 223.86 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 for castings
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
For the purposes of this document, the terms and definitions given in GB/T 5611 and the following apply.
3.1
relevant wall thickness
section of the casting to which the determined mechanical properties shall apply
3.2
side-by-side cast sample
sample cast in the same mould or by the casting system, arranged with the casting side by side
4 Designation of gray cast iron
4.1 Gray cast irons shall be designated according to GB/T 5612.
4.2 Based on the minimum tensile strength measured by the tensile sample machined from a separately cast sample with a diameter of φ30mm, the gray cast irons are classified into 8 grade designations: HT100, HT150, HT200, HT225, HT250, HT275, HT300 and HT350, as shown in Table 1.
4.3 Based on the maximum Brinell hardness measured on castings with relevant wall thickness of 40mm < t ≤ 80mm, the gray cast irons are classified into six grades: HT-HBW155, HT-HBW175, HT-HBW195, HT-HBW215, HT-HBW235 and HT-HBW255, as shown in Table 2.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Designation of gray cast iron
5 Production method and chemical composition
6 Technical requirement
6.1 Mechanical properties
6.2 Graphite structure
6.3 Machining allowance, dimensions, dimensional tolerance, geometric shape and geometric tolerance
6.4 Weight tolerance
6.5 Surface quality
6.6 Casting flaws
7 Sample preparation
7.1 General
7.2 Sample type
7.3 Tensile sample
7.4 Samples for hardness test
8 Test method
8.1 Tensile test
8.2 Hardness test
8.3 Chemical analysis
8.4 Graphite structure
8.5 Non-destructive testing
8.6 Dimensions, dimensional tolerance and geometric tolerance
8.7 Defects detection
8.8 Other alternative test methods
9 Inspection rules
9.1 Batch division
9.2 Chemical composition analysis
9.3 Tensile strength test
9.4 Hardness test
9.5 Test validity
9.6 Judgment of test and re-test results
9.7 Preservation of test data
9.8 Sample preservation
10 Marking, quality certificate, surface protection, packaging, storage and transportation
10.1 Casting marking
10.2 Quality certificate
10.3 Face protection, packaging, storage and transportation
Annex A (Informative) Mechanical and physical properties of gray cast iron
Annex B (Informative) Relationship between hardness and tensile strength of grey cast irons
Annex C (Informative) Relationship between tensile strength, hardness and wall thickness of grey iron castings
Annex D (Informative) Cross-references of GB/T 9439 grade designations to other standard grades of grey cast irons
Bibliography
