Hi Chrome Castings

Alloy white Iron castings are used in the power, mining, cements, construction and other industries for applications where maximum abrasive wear resistance required with toughness being of lesser importance. Excellent abrasion resistance is obtained from these alloys because their micro structures contain 20%-40% of very hard carbides embedded in matrices which consist of martensite, bainite, austenite, secondary carbides. In National and International standards it is used to specify a minimum of around 550 Brinnel hardness and the alloy are divided into two broad groups; the well known Ni-Hard or Nickel-Chromium type and the High Chromium grades. The Chromium iron contains 12-25% Cr.

For a given iron the abrasion resistance is usually improved as the carbon content is raised owing to the greater volume of eutectic carbides which form on solidification, but at the same time the toughness and resistance to premature breakage is decreased. Additionally, the matrices structure can affect both wear and spalling resistance so that care is needed in the selection of the best iron for a given application.

An important consideration in the selection of abrasion-resistant irons and steels is their resistance to fracture. The toughness of white irons is as difficult to quantify as is resistance to abrasion.