The high-alloy white cast irons fall into two major groups:
Nickel-chromium white irons, which are low-chromium alloys containing 3 to 5% Ni and 1 to 4% Cr, with one alloy modification that contains 7 to 11% Cr,
Chromium-molybdenum irons containing 11 to 23% Cr, up to 3% Mo and often additionally alloyed with nickel or copper.
The nickel-chromium irons are also commonly identified as Ni-Hard types 1 to 4.
Ni-Hard Casting or Nickel-Chromium White Irons
The oldest group of high-alloy irons of industrial importance, the nickel-chromium white irons, or Ni-Hard irons, has been produced for more than 50 years and is very cost-effective materials for crushing and grinding.
Ni-Hard is a metal with chrome content of 1.4% to 28%. It is an abrasive iron for low and high stress abrasion in Mining, Milling, and Earth Handling uses.
It is also used extensively in the Power Plant Industry, Brick Plant Industry, Asphalt Industry, Cement Industry, and Rock Crushing Industry.
The optimum composition of a nickel-chromium white iron alloy depends on the properties required for the service conditions and the dimensions and weight of the casting.