'The Effect of Various Heat Treatn1ents on the Hardness of Some Nigerian Steels
No Thumbnail Available
Files
Date
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Description
Two indig~nous steel, NST 37-2 and NST 60Mn were sruJi~d ro detem1ine rhe
effect of various heat treannent!: on c.'leir hardness. Resulrs indicate lha! warer seems to be m•l>t
efficient quenching medium where maximum hardne$s is rcquin:d. Howel'er, when: har\iness
can be sacrificed, mineral oil can be used for qucn.;hing. NST 60Mn SLC:el, wilh higher
manganese and carbon contents sbowed greater hardness at fast cooling rate. This grearer
hardness was due to the greater amount of mancnsitic rransfonnation and precipitation
hardening of carbides (Fe3C)._ Tbe air-cooled samples did nor sh'"' much increase in hardness
·because, !he stee-ls transfoml more imo ferrit~ and \'tl)' lirrJc of pearlire. The lechnologi;:~l
importance of rhe results obuined in relation to Nigerian Stmcrural Adjusuncnl Programme
(SAP} are discussed.
Keywords
TJ Mechanical engineering and machinery