Cast Iron Mach Inability: The Effect of Aging on Material Properties Determines the Optimal Machining Time


Understanding how age strengthening affects machinability enables manufacturers to schedule the optimal window for machining. Aging studies in quenched iron-based alloys indicated a three stage precipitation process. In some cases, a dip in strength is observed during the start of the aging process. The machinability test articles recommended by the American Foundry Society were used for facing cuts on a computer numeric control lathe. These test articles were produced in a laboratory using nobake molds and in industrial metalcasting facilities using green sand molds. Pearlite/ferrite cast irons with variations in carbon equivalent from 3.9% to 4.3% were tested in as-cast condition and after 25 days of natural aging. A reverse type of dependency appeared in which the cutting force decreased when the increasing hardness was due only to natural aging in each iron.


Materials Science and Engineering

Keywords and Phrases

Age strengthening; American foundry societies; Carbon equivalent; Computer numeric control; Machinability tests; Metalcasting facilities; Optimal machining; Precipitation process; Optimization; Precipitation (chemical); Cast iron

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Article - Journal

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© 2013 American Foundry Society, All rights reserved.

Publication Date

01 Sep 2013

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