Microstructure and Mechanical Properties of ADI Depending on Austenitization Methods and Parameters

T. Giętka, T. Szykowny
2012 Archives of Foundry Engineering  
Ductile iron was quenched using two-variant isothermal transformation. The first treatment variant consisted of one-phase austenitization at a temperature t γ = 830, 860 or 900°C, cooling down to an isothermal transformation temperature of 300 or 400°C and holding from 8 to 64 minutes. The second treatment variant consisted of two-phase austenitization. Cast iron was austenitizied at a temperature t γ = 950°C and cooled down to a supercritical temperature t γ' = 900, 860 or 830°C. Isothermal
more » ... 30°C. Isothermal transformation was conducted under the same conditions as those applied to the first variant. Ferrite cast iron was quenched isothermally. Basic strength (R p0.2 , R m ) and plastic (A 5 ) properties as well as matrix microstructure and hardness were examined. As a result of heat treatment, the following ADI grades were obtained: EN-GJS-800-8, EN-GJS-1200-2 and EN-GJS-1400-1 in accordance with PN-EN 1564:2000 having plasticity of 1.5÷4 times more than minimum requirements specified in the standard.
doi:10.2478/v10266-012-0029-6 fatcat:x7qe3phscfb4vhqriikvoxy254