Investigation of Thermo-Magnetic Processing in Application to Heavy Duty Truck Suspension Components

Makiewicz, Kurt¹  Yurek, Theodore¹  Farrell, Brian¹  Youril, Aaron¹  Ludtka, Gerard Michael² 

[1] Hendrickson ATG, Woodridge, IL (United States);Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

关键词: Thermomagnetic processing;   

DOI  :  10.2172/1257906
RP-ID  :  ORNL/TM--2016/181
PID  :  OSTI ID: 1257906
Others  :  Other: ED2802000
Others  :  CEED492

美国|英语

来源: SciTech Connect

【 摘 要 】

Thermomagnetic processing (TMP) was examined as a methodology for increasing transformation rate during heat treatment in steel tubes. Two potential benefits were investigated, reduced energy consumption and improved mechanical properties. It is possible to reduce energy consumption with TMP by allowing tempering at lower temperatures and shorter times. Improved mechanical properties are possible by allowing a more copious distribution of fine carbides during tempering of martensite. Improved mechanical properties are also possible by quenching under a magnetic field after austenitization by formation of martensitic twins. The experiments in this work allowed for the following conclusions: the samples could not be quenched fast enough to transform the entire wall thickness to martensite; the knee of the Continuous Cooling Curve (CCT) curve was shifted to the left when quenching following austenitizing in a magnetic field. The magnetic field during tempering did enhance the kinetics and allowed fine carbides to form. Since the through wall thickness was not hardened, the bulk mechanical properties were unaffected by the magnetic field. Hardness measurements after hardening showed that hardening in a magnetic field >0.5T resulted in a significant reduction in hardness. Combined with the inadequate cooling rate it was not possible to properly harden the samples. Tempering at 600 C without a magnetic field resulted in no formation of carbides, but tempering at 600 C and 450 C with a 1-2T field resulted in carbide formation in all samples.