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ML00062 - Apr.2017

Inconel 718 Lock Nut with Polymer Insert

Micrographic detail of the nut at the thread, presenting a granular austenitic structure free from cold forming effects.

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Micrographic detail of the at the thread, presenting a austenitic free from cold forming effects.
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Material

NiCrFe Alloy
  • UNS N07718
Ds

Description

The was evaluated to be adopted in seawater environment but the high hardness level of the nut at the polymeric insert position, due to the cold forming process, makes it non suitable for conditions due to a possible .

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Chemistry (% in weight)

Nut Analysis

52.8Ni; 17.0Cr; 20.3Fe; 3.1Mo; 0.1W; 4.9Nb; 0.9Ti; 0.6Al; 0.06C; 0.03Mn; 0.09Si; 0.008S; 0.004P.

Associated Images
Micrography of the nut in the longitudinal direction, in the center of the thickness, presenting a granular austenitic structure free from detrimental phases.
475
VIEW
ML00062 / Apr.2017
Inconel 718 Lock Nut with Polymer Insert
M - NiCrFe AlloyP - Cold FormedAp - PipingCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - In the Center of the Thickness
The nut was sectioned in the longitudinal direction to reveal the position of the Nylon insert.
59
VIEW
ML00062 / Apr.2017
Inconel 718 Lock Nut with Polymer Insert
M - NiCrFe AlloyP - Cold FormedAp - PipingCd - Typical manufacturing
Cm - Aspect Before AnalysisDf - Transverse Section
Micrography of the nut in the longitudinal direction, at the thread, presenting a granular austenitic structure free from detrimental phases or cold forming effects.
56
VIEW
ML00062 / Apr.2017
Inconel 718 Lock Nut with Polymer Insert
M - NiCrFe AlloyP - Cold FormedAp - PipingCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Machined Thread
Micrographic detail of the nut at the thread, presenting a granular austenitic structure free from cold forming effects.
52
VIEW
ML00062 / Apr.2017
Inconel 718 Lock Nut with Polymer Insert
M - NiCrFe AlloyP - Cold FormedAp - PipingCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Machined Thread
Micrography of the nut in the longitudinal direction, at the Nylon insert position, showing a cold formed region at the end of the nut, with high hardness levels (about 600 HV100g).
53
VIEW
ML00062 / Apr.2017
Inconel 718 Lock Nut with Polymer Insert
M - NiCrFe AlloyP - Cold FormedAp - PipingCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Strain Hardened
Micrographic detail of the nut at the cold formed region where the nut was bent over the Nylon insert. It is possible to see strain hardened structures (600HV 100g).
41
VIEW
ML00062 / Apr.2017
Inconel 718 Lock Nut with Polymer Insert
M - NiCrFe AlloyP - Cold FormedAp - PipingCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Strain Hardened