MALSTAANG OCH FOERFARANDE FOER SELEKTIV HAERDNING AV STAALSTAENGER, SPECIELLT MALSTAENGER

摘要

A rod having end portions of a hardness characteristic of a pearlitic microstructure, the remainder comprising an annular outer region and a core region, at least the outer region having a surface hardness greater than Rockwell C 50. A method of producing heat treated rods involves passing a heated rod through at least one quench zone, initiating a liquid quench after the leading end of the rod has emerged from the quench zone and turning off the liquid quench before the trailing end of the rod enters the quench zone.