Accession Number:

ADA280452

Title:

Mechanical Performance of Austempered Ductile Iron.

Descriptive Note:

Final rept. Feb-Dec 1993

Corporate Author:

COLORADO SCHOOL OF MINES GOLDEN

Personal Author(s):

Report Date:

1994-04-01

Pagination or Media Count:

37.0

Abstract:

Plates of Austempered Ductile Iron ADI containing, in mass pct, 3.7 C. 2.7 Si, 0.97 Ni and 0.27 Mn were heat treated to ASTM 897 Grade 1 and 3 tensile properties and subjected to tensile testing at temperatures between -80 and 120 deg C. Room temperature yield and ultimate tensile strengths met specifications but values of elongation were lower than expected. The retained austenite contents contributed to lowered yield strengths during low temperature testing and increased ultimate tensile strengths and ductilities during high temperature testing. These changes in properties were related to the effects of temperature on the strain-induced transformation of austenite to martensite. The lower than expected ductility of the ADI specimens was related to microporosity, differences in graphite nodule distributions, differences in strain hardening related to austenite stability, and the ductile-to-brittle fracture transition of the matrix ferrite with decreasing temperature. Ductile iron, Austempering, Mechanical properties, Austenite transformation.

Subject Categories:

  • Inorganic Chemistry
  • Metallurgy and Metallography
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE