Metal Casting

AQL Acceptable Quality Level. A quality level established on a prearranged system of inspection using samples selected at random.

As-cast condition Casting without subsequent heat treatment.

Backing sand The bulk of the sand in the flask. The sand compacted on top of the facing sand that covers the pattern.

Binder The bonding agent used as an additive to mold or core sand to impart strength or plasticity in a “green” or dry state. Read more

Mechanical Properties of Malleable Iron

The different grades of malleable iron are essentially the result of different heat treatments. Just as a medium carbon steel can be heat treated to a wide range in properties so can malleable iron, but malleable is even more versatile. The combined carbon content, on which heat treatment depends, can be adjusted from none, as when the microstructure is entirely ferritic, to that of a fully pearlitic structure. Read more

Mechanical Properties of Cast Carbon and Low Alloy Steels

For the purpose of this article, carbon steels are considered to be those steels in which carbon is the principal alloying element. Other elements that are present and that, in general, are required to be reported are manganese, silicon, phosphorous and sulfur. In a sense, all of these elements are residuals from the raw materials used in the manufacture of the steel, although the addition of manganese is often made during the steel making process to counter the deleterious effect of sulfur and silicon is added to aid in deoxidation. Read more

White and High Alloy Irons

An important group of alloyed irons that fall outside of the ordinary types of Alloy Die castings have been designated the white and high alloy irons, or the special irons. The high alloy irons are considered separately because their alloy content exceeds 3% and they cannot be produced by ladle additions to irons of otherwise standard compositions.

The high alloy irons are usually produced in foundries that are specially equipped to produce the highly alloyed compositions. These irons are often melted in electric arc or induction furnaces, which provide for precise control of composition and temperature. The high alloy irons are sold at premium prices and are expected to outperform ordinary compositions in applications that involve severe service conditions. The foundries that produce these irons may be equipped with heat treating furnaces and quenching equipment or cooling facilities to provide for the most economical use of alloys. Read more