This standard is based on ISO 5922-81 "Malleable Cast Iron".
1 Subject and the Aspects Covered
This standard specifies the material, acceptance of delivery and technical specification of malleable iron castings.
This standard is applicable to mold casting malleable iron castings with sand mold or heat conductivity and may be used as reference for malleable iron castings with other mold.
2 Normative References
GB 5612 Code for Representing Cast Iron
GB 6060.1 Roughness Comparison Specimens Cast Surfaces
GB 6414 Dimensional Tolerances for Castings
GB 228 Method for Tensile Test of Metal
GB 231 Metallic Materials - Brinell Hardness Test
GB 223.1~223.5 and GB 223.12 Methods for Chemical Analysis of Iron, Steel and Alloy
JB 2122 Ferritic Malleable: Metallurgical Phase Standard
GB 2828 Sampling Procedures and Tables for Lot-by-lot Inspection by Attributes
3 Terms
3.1 Malleable iron castings
The malleable iron casting is high tenacity castings acquired by changing the metallographic structure or composition of white cast iron blank by graphitization or oxidation decarburization heat treatment.
3.2 Sample
It refers to the casting provided to purchaser for inspection before the castings being formally put into production.
3.3 First piece
The first batch of castings during formal production.
4 Classification and Grade of Malleable Cast Iron
4.1 Classification
The malleable cast iron is divided into two types according to chemical composition, heat treatment process and different characteristic and metallographic structure.
4.1.1 Black heart malleable cast iron and pearlite malleable cast iron
Metallographic structure of black heart malleable cast iron: mainly of ferritic matrix +group flocculent graphite.
