Back to Nodular Cast Iron
ML00154 - Jan.2019

High Strength Cast Iron Crankshaft

Micrographic detail by scanning electron microscopy, Nital etched, of the ferrite microstructure around a graphite nodule.

23

30
Micrographic detail by , Nital etched, of the around a graphite nodule.
M

Material

Nodular Cast Iron
  • ASTM A 536 100-70-03
  • UNS F34800
Ds

Description

The crankshaft is surface hardened by localized . The center of the presents in a - matrix. The are and forms a 3 mm hardened layer of , and a small amount of . The quenching heat treatment is very quick to avoid graphite dissolution, and the tempering temperature is low to maintain the high surface hardness.

C

Chemistry (% in weight)

Shaft Analysis

3.96C; 2.36Si; 0.51Mn; 0.022P; 0.007S; 0.10Cr; 0.3Ni; 0.53Cu; 0.003V; 0.020Mg.

Associated Images
General view of the nodular cast iron crankshaft, 240 mm long, in process of heat treatment. The main and rod bearings, 54 mm diameter, are heat treated by localized quenching and tempering.
1018
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Aspect Before AnalysisDf - General View
Micrography of a crankshaft longitudinal section at the shaft edge, in the as polished condition, presenting nodular graphite, well distruibuted.
139
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - As polished micrographyDf - At the Surface
As polished micrography of the crankshaft at the shaft edge, close to the surface. Graphite in nodules.
126
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - As polished micrographyDf - Graphite in Nodules
As polished micrographic detail of the graphite in nodules, close to the surface of the shaft edge, in a longitudinal section.
114
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - As polished micrographyDf - Graphite in Nodules
Macrography of a longitudinal section of the crankshaft showing the rod bearing in the center (the rod is 54mm diameter), as well as two main bearings in both lateral sides. It is possible to see that the surface was heat treated and the hardened layer is about 3mm deep from the surface.
100
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - NItal Etched MacroDf - Longitudinal Section
Macrographic detail of the hardened layer, about 3mm deep from the surface. Important to observe that the bearing is not heat treated in the radius, only in the contact area. The hardness at the surface is 430HV and the hardness in the base metal is 260HV.
100
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - NItal Etched MacroDf - Surface Layer
Micrography of the crankshaft at the surface, in the radio that is not heat treated. The microstructure is nodules of graphite in a ferritic and pearlitic matrix, predominantly pearlitic.
95
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - At the Surface
Micrography of the crankshaft close to the radio that is not heat treated. Graphite in nodules and a ferritic and pearlitic matrix, predominantly pearlitic.
81
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - Matrix of ferrite and pearlite
Micrographic detail of the graphite nodules and a ferritic and pearlitic matrix, predominantly pearlitic.
82
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - Matrix of ferrite and pearlite
Micrography of the shaft at the surface, in a heat treated position. Graphite in nodules. Dark blue martensitic microstructure around the nodules and white islands of martensitic with retained austenite microstructure (not clearly identified at this low magnification).
68
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - At the Surface
Micrography of the shaft very close to the surface, in a heat treated position. Graphite in nodules. Dark blue martensitic microstructure around the nodules, brown yellow martensite and white islands of martensitic with retained austenite microstructure.
65
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic detail of the graphite in nodules, dark blue martensitic microstructure around the nodules, brown yellow martensite and white yellow islands of martensitic with retained austenite microstructure.
60
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - Martensite
Micrography of the shaft below the heat treated surface, in the middle of the hardened layer. There is a gradient in the colours. Hardened surface in the top of the figure and nucleous in the bottom.
49
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - Surface Layer
Micrography of the shaft below the heat treated surface. At this position, in the middle of the hardened layer , it is possible to see also white regions of ferrite, very close to the graphite nodules.
47
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic detail of the hardened layer, presenting the graphite nodules, brown and yellow martensite regions and white areas of ferrite, close to the nodules.
46
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - Martensite
Micrography of the shaft below the heat treated surface, close to the limit of the hardened layer. There is a gradient in the colours. Hardened surface in the top of the figure and nucleous in the bottom.
45
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - Surface Layer
Micrography of the shaft below the heat treated surface. At this position, close to the limit of the hardened layer , it is possible to see the brown yellow martensite and ferrite around the graphite nodules.
38
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic detail of the brown yellow martensite and ferrite around the graphite nodules.
39
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - Martensite
Micrography of the crankshaft in the center of the thickness. The microstructure is nodules of graphite in a ferritic and pearlitic matrix, predominantly pearlitic.
34
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - In the Center of the Thickness
Micrography of the crankshaft in the center of the thickness presenting nodules of graphite in a ferritic and pearlitic matrix, predominantly pearlitic.
34
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - Matrix of ferrite and pearlite
Micrographic detail of the graphite in nodules and a ferritic-pearlitic matrix.
32
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - Matrix of ferrite and pearlite
Micrographic detail, by scanning electron microscopy, of the graphite in nodules and a ferritic-pearlitic matrix.
32
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by SEMDf - Graphite in Nodules
Micrographic detail by scanning electron microscopy, Nital etched, of the ferrite microstructure around a graphite nodule.
30
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by SEMDf - Ferrite and Pearlite
Micrographic detail of the pearlite in the matrix.
29
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by SEMDf - Pearlite
Micrography of the shaft at the surface in a heat treated position. The graphite nodule is degradating due to temperature and adjacent the microsctructure is martensitic.
27
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by SEMDf - Graphite in Imperfect Nodules
Micrographic detail of the graphite nodule surrounded by martensite.
30
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by SEMDf - Martensite
Micrographic detail of the martensite.
32
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by SEMDf - Martensite
Micrographic detail of the tempered martensite, and small regions (shinning poligons) of austenite-martensite.
29
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by SEMDf - Martensite