This specification covers general requirements and corresponding test methods for castings made of high-silicon molybdenum ferritic iron (SiMo). The requirements are prescribed for castings with microstructures of spheroidal graphite (SG) SiMo iron, compacted graphite (CG) SiMo iron, and mixed graphite or medium-nodularity graphite (MG) SiMo iron. MG iron microstructure is comprised of a mixture of spheroidal and compacted graphite shapes.

1.1 This specification covers castings made of high-silicon molybdenum ferritic iron, commonly known as SiMo. This specification includes castings with microstructures of spheroidal graphite (SG) SiMo iron, compacted graphite (CG) SiMo iron, and mixed graphite or medium-nodularity graphite (MG) SiMo iron. MG iron microstructure comprises a mixture of spheroidal and compacted graphite shapes. This standard specifies the condition, chemical composition, microstructure, and other technical requirements of three grades of ferritic cast irons, specified as SG SiMo, MG SiMo, and CG SiMo.

1.2 No precise quantitative relationship can be stated between the properties of iron in the various locations of the same casting or between the properties of castings and those of a test specimen cast from the same iron.

1.3 The values stated in SI units are to be regarded as standard. All chemical compositions are in mass percentage. No other units of measurement are included in this standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.