Accession Number : AD0682796

Title :   ON THE NATURE OF DISTRIBUTION OF CARBIDE PHASE IN A CARBONIZED LAYER OF ALLOYED STEELS,

Corporate Author : FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Natapov,B. S. ; Vasilenko,G. I. ; Olshanetskii,V. E.

Report Date : 26 JUN 1968

Pagination or Media Count : 13

Abstract : Fourteen specimens made from Armco Fe with added Cr (3 specimens with Cr 1.26-2.00%, or Ni (4 specimens with 1.57-4.40%), or W (2 specimens with W 0.83-1.58%), or Mo (2 specimens with Mo 0.47-0.72%) were carburized for 12 hrs. at 920 and then cooled at the rate of 40 degrees/hr. Some of the specimens were reheated to 680 and held for 10 hrs. Subsequently the microstructure was detd. microscopically. During retarded cooling of steel within the temp. interval Ac sub m to A sub 1 the elements which are surface-active with regard to austenite, e.g., W, Mo, contribute toward coalescence and spheroidization of the carbide network, while non-surface-active elements (toward austenite), e.g., Ni, Mn, Cr preserve this network. Elements which are surface-active with regard to ferrite, e.g., Cr, increase surface tension at the ferrite-carbide phase boundary and thereby contribute toward spheroidization of finely lamellar pearlite during annealing at temps. slightly below A sub 1. It is recommended that alloying elements be introduced which are surface active toward austenite, e.g., W, Mo, into those steels which will be carburized. (Author)

Descriptors :   (*STEEL, *CASE HARDENING), PHASE STUDIES, CARBIDES, MICROSTRUCTURE, CHROMIUM ALLOYS, NICKEL ALLOYS, TUNGSTEN ALLOYS, MOLYBDENUM ALLOYS, SURFACE ACTIVE SUBSTANCES, USSR

Subject Categories : Properties of Metals and Alloys
      Fabrication Metallurgy

Distribution Statement : APPROVED FOR PUBLIC RELEASE