Product Description and Process
machining grey cast iron class 30 40 sae j431 g3000 material custom iron castings
Production process: green sand molding, pre-coated sand molding and resin sand molding which can produce iron castings from 50 gram to 2000 kilograms
Machining process: CNC machine, machining center, lathe, mill machine, drill machine, etc.
Surface treatment process: paint coating, electrophoretic coating, electrogalvanizing coating, black oxide coating, powder coating, etc.
Product Material and Uses
Normally produce with gray iron HT200, HT250, ductile iron 65-45-12, 60-40-18, 80-55-06, 80-60-03, etc.
The grey/gray iron casting products are widely used for Auto-cars, trains, trucks, vehicle components, mining machinery components, agricultural machinery parts, textile machinery parts, construction machinery parts, etc.
What is Grey Cast Iron?
Grey cast iron (a.k.a. gray iron) is a type of iron found in castings known for its grey color and appearance caused by graphite fractures in the material. Specifically, what makes grey iron “grey iron,” is the graphite flake structure that is created during the cooling process from the carbon that is in the component.
Grey iron is a result of both the materials used and the process used to cast a part. In other words, the properties of the grey iron will change depending on what materials are melted together to pour into the mold as well as the process that is used for casting (it is primarily the cooling part of the process that defines the characteristics of the cast part versus other parts of the process.).
Classification of Grey Iron Classes
In the United States, the classification for grey iron is usually set using the ASTM International standard A48. ASTM A247 is also commonly used to describe the graphite structure. Grey iron is grouped into classes which correspond with its minimum tensile strength in thousands of pounds per square inch (ksi); (i.e. class 20 grey iron has a minimum tensile strength of 20,000 psi (140 MPa)). Other ASTM standards that deal with gray iron include ASTM A126, ASTM A278, and ASTM A319.
Class 20 grey iron has a ferrite matrix and a high carbon equivalent. Higher strength gray irons, up to class 40, have lower carbon equivalents and a pearlite matrix. To get grey iron above class 40 requires alloying to provide solid solution strengthening. Grey iron can also be heat treated which modifies the matrix giving the cast iron greater strength. Class 80 is the highest class available for grey iron and it makes the iron have high tensile strength but low impact resistance because class 80 parts are more brittle.
Below is a reference chart of other ASTM standards affecting grey iron.
ASTM A395 & ASME SA395: ferritic ductile iron pressure-retaining castings for use at elevated temperatures
ASTM A439: austenitic ductile iron castings
ASTM A476 & ASME SA476: ductile iron castings for paper mill dryer rolls
ASTM A536 & SAE J434: ductile iron castings
ASTM A571 & ASME SA571: austenitic ductile iron castings for pressure-containing parts suitable for low-temperature service
ASTM A874: ferritic ductile iron castings suitable for low-temperature service
ASTM A897: austempered ductile iron castings