This standard specifies the classification and designation, technical requirements, test methods, inspection rules, marking of castings, surface protection, packaging, storage and transportation requirements of malleable iron castings.
This standard is applicable to malleable iron castings cast into sand moulds or moulds of comparable thermal conductivity.
Other mold casting malleable iron castings may use it by reference.
2 Normative References
The following standards contain provisions which, through reference in this standard, constitute provisions of this standard. For dated reference, subsequent amendments to (excluding correction to), or revisions of, any of these publications do not apply. However, the parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards. For undated references, the latest edition of the normative document referred to applies.
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 223.59 Iron steel and alloy-Determination of phosphorus content-Bismuth phosphomolybdate blue spectrophotometric method and antimony phosphomolybdate blue spectrophotometric 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 223.63 Methods for Chemical Analysis of Iron, Steel and Alloy; The Sodium (Potassium) Periodate Photometric Method for the Determination of Manganese Content(GB/T 223.63-1988, neq ASTM E350: 1985)
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 228 Metallic Materials-Tensile Testing at Ambient Temperature (GB/T 228-2002, ISO 6892: 1998, EQV)
GB/T 231.1 Metallic Materials-Brinell Hardness Test-Part 1:Test Method (GB/T 231.1-2009, ISO 6506-1: 2005, MOD)
GB/T 1031 Geometrical product specifications(GPS)-Surface texture: Profile method-Surface roughness parameters and their values
GB/T 1958 Geometrical product Specifications (GPS)-Geometrical tolerance-Verification prescription
GB/T 4336 Standard Test Method for Spark Discharge Atomic Emission Spectrometric Analysis of Carbon and Low-alloy Steel (Routine Method)
GB/T 5612 Code for Representing Cast Iron (GB/T 5612-2008, ISO 15931: 2004, MOD)
GB/T 6060.1 Roughness Comparison Specimens-Cast Surfaces (GB/T 6060.1-1997, eqv ISO 2632-3: 1979)
GB/T 6414 Castings-System of Dimensional Tolerances and Machining Allowances (GB/T 6414-1999, eqv ISO 8062: 1994)
GB/T 11351 Mass Tolerances for Castings
GB/T 25746 Metallographic Test for Malleable Cast Iron
JB/T 5105 Casting form Pattern draft
3 Classification and Designation of Malleable Cast Iron
3.1 Classification
Malleable cast iron are classified into two types (Type I: black heart malleable iron and pearlite malleable cast iron; Type II: white heart malleable cast iron) according to different performance and metallographic structures due to chemical composition and heat treatment technology.
3.1.1 Black heart malleable iron and pearlite malleable cast iron
Metallographic structure of black heart malleable iron: mainly of ferritic matrix +group flocculent graphite.
Metallographic structure of pearlite malleable cast iron: mainly of pearlitic matrix + group flocculent graphite.
3.1.2 White heart malleable cast iron
The metallographic structure of white heart malleable cast iron is dependent on section size, as described below. Figure 1 shows the metallographic structure changes depending on the thickness of the casting wall.
a) Thin section = ferrite (+ pearlite + graphite aggregate);
b) Thick section see Figure 1.
