# Microstructure of Modified 9Cr-1Mo Steel Manufactured via Laser Powder Bed Fusion

https://mdr.nims.go.jp/datasets/32df4314-4b7c-4fbe-8d38-72cf1fc9172d

## File

- [epri2024p0365.pdf](https://mdr.nims.go.jp/filesets/4b0f8f0d-f170-4d96-8c84-d193574b6b12/download) ([Detail](https://mdr.nims.go.jp/filesets/4b0f8f0d-f170-4d96-8c84-d193574b6b12.md))

## Id

32df4314-4b7c-4fbe-8d38-72cf1fc9172d

## Local identifier



## Visibility

open_to_public

## State

published

## Created at

2024-11-28T00:33:08.492782Z

## Updated at

2024-12-04T23:30:58.525882Z

## Published at

2024-12-04T23:30:58.606015Z

## Doi



## First published url

https://doi.org/10.31399/asm.cp.am-epri-2024p0365

## Date published

2024-10-15

## Recorded date published



## Resource type

conference_paper

## Manuscript type

vor

## Collection



## Title

- title: Microstructure of Modified 9Cr-1Mo Steel Manufactured via Laser Powder Bed
    Fusion
  title_type: original
  lang: en

## Description

- description: Modified 9Cr-1Mo steel was manufactured via laser powder bed fusion
    (LPBF) using gas atomized powders under various building conditions. Dense samples
    were obtained at an energy density of 111-125 J/mm3. As-built samples were subjected
    to a normalization and tempering heat treatments. The microstructure of the as-built
    sample exhibits a duplex structure, comprising coarse columnar δ-ferrite grains
    and fine martensite grains. In addition, a small amount of retained austenite
    phase was observed at the interface between δ-ferrite and martensite. The formation
    of δ-ferrite is attributed to the extremely rapid solidification that occurs during
    the LPBF process, while martensite is obtained through the phase transformation
    because of the thermal cycles experienced during the process. The area fraction
    of δ-ferrite and martensite can be controlled by adjusting the LPBF parameters.
    Typical as-built microstructure morphology characterized by the columnar δ- ferrite
    was eliminated after the heat treatments, resulting in a tempered martensitic
    microstructure that is identical with that obtained through the conventional process.
    However, an increase in prior austenite grain size was observed when the area
    fraction of δ-ferrite in the as-built condition was high, due to faster phase
    transformation kinetics of martensite than that of δ-ferrite during the normalization.
    This suggests that the prior austenite grain size can be controlled by optimizing
    the area fraction of δ-ferrite and martensite in the as-built microstructure.
  description_type: abstract
  lang: und

## Creator

- name: Tomotaka Hatakeyama
  role: author
  orcid: https://orcid.org/0000-0002-2904-8177
  organization: National Institute for Materials Science
  ror: https://ror.org/026v1ze26
- name: Kota Sawada
  role: author
  orcid: https://orcid.org/0000-0001-7780-1648
  organization: National Institute for Materials Science
  ror: https://ror.org/026v1ze26
- name: Masaru Suzuki
  role: author
- name: Makoto Watanabe
  role: author
  orcid: https://orcid.org/0000-0002-5064-9583
  organization: National Institute for Materials Science
  ror: https://ror.org/026v1ze26

## Contact agent



## Publisher

organization: ASM International

## Managing organization



## Keyword

- subject: Laser powder bed fusion
  schema: not_defined
- subject: microstructure
  schema: not_defined
- subject: heat resistant steel
  schema: not_defined

## Rights

- description: "Copyright © 2024 ASM International®\r\nAll rights reserved.\r\n"
  identifier: http://rightsstatements.org/vocab/InC/1.0/

## Other identifier(s)



## Data origin

- data_origin_type: other

## Embargo



## Journal

- title: Advances in Materials Technology for Power Plants
  issn: '29944031'
  volume: '84871'
  start_page: 365
  end_page: 372

## Conference



## Related item



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## Instrument



## Instrument operator



## Instrument managing organization



## Measurement method



## Specimen



## Chemical composition



## Structure for specimen



## Structural feature for specimen



## Specific property for specimen



## Process for specimen treatment



## Computational method



## Energy level/transition state



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## Custom property



## Fileset

- id: 4b0f8f0d-f170-4d96-8c84-d193574b6b12
  filename: epri2024p0365.pdf
  content_type: application/pdf
  size: 2086537
  md5: b34827faebb850c795988f69faa77f0d

## Thumbnail

fileset_id: 4b0f8f0d-f170-4d96-8c84-d193574b6b12
filename: epri2024p0365.pdf