ON THE NATURE OF DISTRIBUTION OF CARBIDE PHASE IN A CARBONIZED LAYER OF ALLOYED STEELS,
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)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 26, 1968
- Accession Number
- AD0682796
Entities
People
- B. S. Natapov
- G. I. Vasilenko
- V. E. Olshanetskii
Organizations
- National Air and Space Intelligence Center