高炭素高クロム鋳鋼の鍛錬性と材質特性

抄録

  Tools of a plug mill for seamless pipe rolling are damaged very shortly when used in heavy mechanical and thermal loading. So improving durability of the tools has been attempted by making them by forging of high carbon and chromium cast steel. Forgeability of high chromium cast steel was tested by hot rolling of 50kg short ingots with chemical composition of 1.2 to 2.0% carbon and 22 to 27% chromium. The structure of the ingot heated at 1,000 to 1,150°C consists of eutectic carbide of Cr₂₃C₆ type and austenitic matrix. After forging by hot rolling, test materials were heat-treated and examined in mechanical properties, characteristics of fatigue strength and improvement of wear at elevated temperatures.
  There are good forgeability of high carbon and chromium cast steel with suitable chemical composition selected by empirical equation of Cr(%)=12+7.7×C(%). Structure and mechanical properties of the materials are greatly improved by hot rolling, especially in toughness, fatigue life and anti-wear properties at elevated temperatures.