Study on Microstructure and Properties of Austempered Ductile Iron Containing Cr

Author of the article:GUO Junbao1 , DONG Shengquan2 , KONG Bing1

Author's Workplace：1. Shanxi Diesel Engine Industry Co., Ltd., Datong 037036, China; 2. Xi'an University of Technology, Xi'an 710021, China

Key Words：austempered ductile iron; yttrium; austempering temperature; microstructure; mechanical properties

Abstract：In order to solve the problems of poor nodularity and microstructure and properties of thick section SG iron containing Cr, 0.2% Yttrium rare earth was added for nodulazition treatment, and five different austempering temperature were selected to study the effect of austempering temperature. Results show that addition of yttrium improved nodularity and nodule count. Low austempering temperature results in a small amount of martensite. With increasing austempering temperature, elongation, impact value and strength are increased, hardness is decreased. Austempering at 300 ℃ can obtain optimized wear resistance.