ASTM A278 PDF
ASTM A Standard Specification for Gray Iron Castings for Pressure- Containing Parts for Temperatures up to Degrees F. Find the most up-to-date version of ASTM A at Engineering Purchase your copy of ASTM A/AM – 01() as a PDF download or hard copy directly from the official BSI Shop. All BSI British.
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Although some production iron foundry facilities have established guidelines for their own capability ashm dimensional control, these controls are typically established through engineering based on the requirements of the application and the needs of the end user. The graphite also gives gray iron an excellent damping capacity because it absorbs the energy and converts it into heat.
Only minor compositional differences to promote the desired matrix microstructure exist among the regular grades. This page was last edited on 16 Novemberat The cooling rate in any particular section factors heavily into the mechanical properties of the iron. Combining values from a28 two systems may result in non-conformance with the standard. New tool materials for economical machining of iron castings are in a continual state of improvement and development.
Malleable iron — In malleable iron, the graphite occurs as irregularly shaped nodules called temper carbon because it is formed in the solid state during heat treatment. Please contact us at webmaster matweb.
These specifications give the aztm tensile and impact levels along with typical Brinell hardness values Table 5. A may be alloyed with Chrome and Copper.
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We advise that you only use the original value or one of its raw conversions in your calculations to minimize rounding error.
Users requiring more precise data for scientific or engineering calculations can click on the property value to see the original value as well as raw conversions to equivalent units. However, ductile iron is replacing malleable iron in many applications because the engineering properties of ductile iron castings are almost identical to that of malleable iron, and ductile iron does not require extensive heat treatment to precipitate graphite.
The silicon promotes good corrosion resistance and increased fluidity when casting. Abrasion Resistant Irons are low in silicon and are generally alloyed with Nickel and Chrome. A287 is an insignificant amount of graphite present in Abrasion Resistant Irons.
The actual properties of the metal in the casting will depend upon its characteristics and the cooling rate of the metal in its various sections.
Aastm Iron has steel like mechanical properties with the castability, machinability, and corrosion resistance of Gray Iron.
In SAE Standard J, tensile strength is not required, but hardness and a minimum tensile strength to hardness ratio are required. Gray ironor grey cast ironis a type of cast iron that has a graphitic microstructure. The two specifications approach the task from different standpoints, but the concept essentially remains the same.
This specification covers gray iron for castings suitable for pressure-containing parts at elevated temperatures. The properties of all cast metals are influenced by the manner in which they solidify and cool. The tips of the flakes act as preexisting notches at q278 stresses concentrate and it therefore behaves in a brittle manner. Iron used in supplying castings shall conform to the required tensile strength.
Ductile Iron Pillow Block.
Alloys | Clinch River Casting
Class 80 is the highest class available, but it is extremely brittle. The different metals within this family are separated further into the following classifications: Grey cast iron’s high thermal conductivity and specific heat capacity are often exploited to make cast iron cookware and disc brake rotors. Link to Active This link will always route to the current Active version of the standard.
Alloy additions may be needed to obtain the higher-strength grades in heavy sections. Malleable iron is ideal for thin-sectioned components that require ductility. It is used for housings where the stiffness of the component is more important than its tensile strength, such as internal combustion engine cylinder blockspump housings, valve bodies, electrical boxes, and decorative castings. To achieve a fully ferritic matrix the alloy must be annealed.
Iron Specifications – Jade Trading Casting Services | Jade Trading
Ductile Iron is commonly known as Nodular Awtm. Because the modulus of elasticity for gray iron is higher in compression than it is in tension, the use of standard structural formulas results in a conservative design.
A typical chemical composition to obtain a graphitic microstructure astmm 2. The damping capacity of gray iron is considerably greater than that of steel and other iron types. The majority of carbon is in the form of iron carbides making it very hard, brittle and in most cases unmachinable.
Higher strength gray irons, up to class 40, have lower carbon equivalents and a pearlite matrix.
Strength and hardness are sensitive to section thickness in gray iron castings. ADI Properties Austempering of ductile iron castings at higher temperatures produces ADI with lower strength and hardness, as well as higher ductility and toughness.
The acceptance of the castings is based on characteristics that w278 metalcasting facility or independent third party can evaluate and control during production.
ASTM A278/A278M – 01(2015)
Grey Iron Compressor Body. In some applications, the finished component is tested in the manner in which it will be used. The graphite has no aa278 strength, so they can be treated as voids.
Another factor affecting graphitization is the solidification rate; the slower the rate, the greater the time for the carbon to diffuse and accumulate into graphite. From Wikipedia, the free encyclopedia. Lower Classes of Gray Iron provide better machinability with higher classes offering strength and wear resistance. Converted from Brinell hardness.
It is named after the gray color of the fracture it forms, which is due to the presence of graphite.