Hardness Wear Resistance and Compressive Strength of Machining High Chromium Cast Iron Containing Lead and Sulphur

Abstract

  High chromium cast irons have poor machinability because of their high hard carbide content. The development of free-cutting high chromium cast irons is therefore desired. In this study machining 2.4 mass % C-15 mass % Cr-1.0 mass % Mo cast irons containing 0 to 0.2 mass % Pb and 0 to 0.4 mass % S were made and the effects of lead and sulphur on hardness, wear resistance and compressive strength of these irons were investigated. The hardness was virtually unaffected by the addition of lead and sulphur. Wear loss of irons with lead was smaller than that of lead free ones under corrosive wear conditions since lead improves the corrosion resistance of iron and suppresses acceleration of wear due to corrosion. Compressive strength of irons containing lead and sulphur decreased slightly compared with that of lead and sulphur free irons. It is evident that machining high chromium cast irons containing lead and sulphur are useful as wear resistant materials.