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ML00158 - Feb.2020

Surface Hardened Carbon Steel Wheel

Micrographic aspect of the rim microstructure at the surface (internal to the wheel), not the heat treated one. The pearlitic structure is not so coarse than in the center of the thickness.

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Micrographic aspect of the rim (internal to the wheel), not the heat treated one. The is not so coarse than .
M

Material

High Carbon Steel
  • ASTM A 504 grade C
  • AISI 1070
Ds

Description

This wheel was in operation for a long time. It is a , wrought, that presents a coarse in the center of the rim, predominantly ; and a localized surface hardening treatment (quenching and tempering) in contact with the runway (wheel tread). At this surface the is and the hardness meets the minimum design requirements of 321HB (Brinell).

C

Chemistry (% in weight)

Product analysis

0.74C; 0.23Si; 0.70Mn; 0.016P; 0.014S; 0.14Cr; 0.08Ni; 0.02Mo; 0.09Cu.

Associated Images
Macrography of a wheel section close to the tread, where the material receives a localized surface hardening by quenching and tempering. The average hardness at the surface is 346HB and in the center is 196HB. The wheel was in operation for a long time and the analyzed part is at the wheel tread.
902
VIEW
ML00158 / Feb.2020
Surface Hardened Carbon Steel Wheel
M - High Carbon SteelP - WheelAp - TransportationCd - Removed From Service
Cm - NItal Etched MacroDf - Transverse Section
Micrography of the wheel in the center of the thickness. The material presents a coarse structure.
88
VIEW
ML00158 / Feb.2020
Surface Hardened Carbon Steel Wheel
M - High Carbon SteelP - WheelAp - TransportationCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - In the Center of the Thickness
Micrography of the wheel in the center of the thickness, presenting a predominantly pearlitic structure and average hardness abot 196HB.
74
VIEW
ML00158 / Feb.2020
Surface Hardened Carbon Steel Wheel
M - High Carbon SteelP - WheelAp - TransportationCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Coarse Structure
Micrographic detail of the coarse pearlitic structure in the center of the wheel thickness. The part presents a wrought structure.
73
VIEW
ML00158 / Feb.2020
Surface Hardened Carbon Steel Wheel
M - High Carbon SteelP - WheelAp - TransportationCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Pearlite
Micrography of the wheel at the surface that was quenched and tempered. The material presents a tempered martensitic structure, with hardness that varied from 327HB to 363HB.
55
VIEW
ML00158 / Feb.2020
Surface Hardened Carbon Steel Wheel
M - High Carbon SteelP - WheelAp - TransportationCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - At the Surface
Micrography of the wheel at the hardened surface, presenting a refined martensitic structure, tempered for average hardness of 346 HB.
50
VIEW
ML00158 / Feb.2020
Surface Hardened Carbon Steel Wheel
M - High Carbon SteelP - WheelAp - TransportationCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - At the Surface
Micrographic detail of the tempered martensitic structure.
50
VIEW
ML00158 / Feb.2020
Surface Hardened Carbon Steel Wheel
M - High Carbon SteelP - WheelAp - TransportationCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic aspect of the rim microstructure at the surface (internal to the wheel), not the heat treated one. The pearlitic structure is not so coarse than in the center of the thickness.
38
VIEW
ML00158 / Feb.2020
Surface Hardened Carbon Steel Wheel
M - High Carbon SteelP - WheelAp - TransportationCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Internal Surface
Micrographic aspect of the pearlitic structure at the surface not heat treated, showing a lower grain size than in the center of the thickness.
35
VIEW
ML00158 / Feb.2020
Surface Hardened Carbon Steel Wheel
M - High Carbon SteelP - WheelAp - TransportationCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Pearlite
Micrographic detail of the pearlitic microstructure in a region where the structure is not so coarse than in the center of the thickness.
30
VIEW
ML00158 / Feb.2020
Surface Hardened Carbon Steel Wheel
M - High Carbon SteelP - WheelAp - TransportationCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Pearlite
Macrography of a wheel section close to the tread, where the material receives a localized surface hardening by quenching and tempering. The average hardness at the surface is 346HB and in the center is 196HB. The wheel was in operation for a long time and the analyzed part is at the wheel tread.
1
VIEW
ML00158 / Feb.2020
Surface Hardened Carbon Steel Wheel
M - High Carbon SteelP - WheelAp - TransportationCd - Removed From Service
Cm - NItal Etched MacroDf - Transverse Section