ASTM A 197/A 197M

This specification covers malleable irons for castings made by the cupola process. The chemical composition of the iron shall be such as to produce materials that meet the mechanical property requirements. The tensile test methods for malleable iron are presented in details. At least three tensile test specimens shall be cast from a representative ladle of iron from each 4-h pour period during the purchasers castings were poured. Only one test specimen need be tested to qualify each pour period and heat treatment batch provided the requirements of this specification are met by the test specimen. The microstructure of the malleable iron shall consist of temper carbon nodules uniformly distributed in a ferritic matrix and shall be free from excessive pearlite, massive carbides, and primary graphite. All castings, on visual examination shall be sound and free from obvious shrinkage and porosity.