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ML00151 - Dec.2018donated by: Ivan Silveira

Ferritic Stainless Steel of a Flatware Fork

Micrography of a fork handle in the longitudinal section, presenting the larger ferritic grains.

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of a fork handle in the , presenting the larger grains.
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Material

Ferritic Stainless Steel
  • AISI 409
  • UNS S40900
Ds

Description

This decorative service fork has been is use for more than 10 years and the non-metallic handle has broken. The objective of this case is to show the fork metallurgical characteristics. It is a , type ( % > 6 x %C ); and the in the longitudinal and are ferritic with grain size variations through thickness in some locations. The region where the fork was cut in fabrication shows and hardening.

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Chemistry (% in weight)

Fork Analysis

0.045C; 0.47Si; 0.25Mn; 0.012P; 0.002S; 11.46Cr; 0.11Ni; 0.007Mo; 0.297Ti; 0.009Nb; 0.03Cu; 0.03Al; 0.04V.

Associated Images
Decorative table service fork, with a non metallic handle that is broken. The metallic part is about 165 mm long and presents two shapes: the scoop and the handle. The scoop is 53mm wide and 73mm long and the handle is about 9 mm wide and 75 mm long.
731
VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - Aspect Before AnalysisDf - General View
The metallic part of the fork handle is about 9mm wide. It was cut in a transverse section and the profile is shown in this figure. The thickness is 1mm and the curvature depth is about 3mm.
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VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - Transverse Section AspectDf - Formed Profile
Micrography of the fork handle in the transverse section, curved, presenting differences between grain size and morphology. In the middle section there are elongated grains and close to the surfaces there are smaller and more equiaxed grains.
81
VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - Micro by OM, HCl + Ethanol + Picric AcidDf - Transverse Section
Micrography of the fork handle in the center of the transverse section, curved, presenting larger ferritic grains with elongated morphology.
70
VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - Micro by OM, HCl + Ethanol + Picric AcidDf - Granular structure
Micrographic detail of the ferritic grains with elongated morphology in the center of the transverse section, curved.
58
VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - Micro by OM, HCl + Ethanol + Picric AcidDf - Ferrite
Lateral view of the fork showing the profile. The scoop convex depth is 10 mm and the handle concave depth is 3 mm. The overal thickness of the part is 1 mm.
53
VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - Aspect Before AnalysisDf - General View
The micrography as polished in the transverse section shows a small amount of inclusions in the steel.
62
VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - As polished micrographyDf - Non Metallic Inclusions
Detail of the non metallic inclusions in the steel. The yellow and black colours and morphologies suggest Ti base and oxides.
65
VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - As polished micrographyDf - Non Metallic Inclusions
The fork scoop is about 53 wide and there is a transition to the handle that is 9mm wide. Exactly at that transition the fork was cut in a longitudinal section and the profile is shown in this figure. The thickness is 1mm and the curvatures of the scoop and handle are in different directions, 3mm depth concave in the handle and 10 mm depth convex in the scoop.
54
VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - Longitudinal Section AspectDf - Formed Profile
Micrography of a longitudinal section of the fork, at the scoop to handle position (scoop to the right of the figure and handle to the left). The full thickness is presented in the image and it is possible to see that in the handle location the ferritic grains are larger in the center of the thickness than close to the surfaces, and in the scoop position the grains tend to be more uniform through the thickness.
50
VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - Micro by OM, HCl + Ethanol + Picric AcidDf - Longitudinal Section
Micrography of a fork longitudinal section, at the handle (close to the transition betwee the scoop and handle). The full thickness is presented in the image and it is possible to see that the ferritic grains are larger in the center of the thickness than close to the surfaces.
49
VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - Micro by OM, HCl + Ethanol + Picric AcidDf - Longitudinal Section
Micrography of a fork longitudinal section, in the center of the thickness, at the scoop position. The ferritic grains are equiaxial and uniform.
49
VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - Micro by OM, HCl + Ethanol + Picric AcidDf - Granular structure
Micrography of a fork handle in the longitudinal section, presenting the larger ferritic grains.
45
VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - Micro by OM, HCl + Ethanol + Picric AcidDf - Granular structure
Micrographic detail of the fork longitudinal section, in the center of the thickness, at the scoop position, showing ferritic grains equiaxial and uniform.
46
VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - Micro by OM, HCl + Ethanol + Picric AcidDf - Ferrite
Micrographic detail of thefork handle longitudinal section, showing large ferritic grains.
40
VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - Micro by OM, HCl + Ethanol + Picric AcidDf - Ferrite
Aspect of the cut surface of the fork tooth in the scoop. The thickness is 1 mm and the fabrication finishing of the surface is polished. The tooth in the center was cut for analysis in the longitudinal section.
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VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - Surface AspectDf - Cut Surface
Micrography of the longitudinal section from the fork tooth in the scoop. The microstructure is the same as in the scoop close to the handle, but at the cut surface the structure presents strong plastic deformation generated by a mechanical cutting.
32
VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - Micro by OM, HCl + Ethanol + Picric AcidDf - Cut Surface
Micrography of the longitudinal section from the fork tooth in the scoop. The microstructure is the same as in the scoop close to the handle, ferritic grains equiaxial and uniform, but at the cut surface the structure presents strong plastic deformation generated by a mechanical cutting.
36
VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - Micro by OM, HCl + Ethanol + Picric AcidDf - Plastic Deformation
Micrographic detail of the strong plastic deformation at the edge of the scoop in the tooth cutting location. The hardness at this region of strong plastc deformation is about 240HV1.
38
VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - Micro by OM, HCl + Ethanol + Picric AcidDf - Plastic Deformation