III. Report on Martensitic Cast Irons

Abstract

The resistance to wear, erosion, and abrasion which is characteristic of martensitic cast irons has brought about their employment in a number of engineering applications. Martensitic cast irons may be produced by heat treatment of an ordinary engineering pearlitic iron; or they may be specially produced and so treated that either of two varieties can be obtained. In one such variety the eutectic filling surrounding the primary grains is allowed to solidify white (cementitic), and in the other it is allowed to solidify grey (graphitic). There are thus two main classes of the martensitic cast irons which are specially made as such; they may be respectively described as “white” and “grey” in character, the former being the harder of the two. The “grey” variety can be made martensitic in the condition as cast, or alternatively a martensitic structure can be produced in it by suitable heat treatment.