Microstructure and Mechanical Properties of 18Ni-300 Maraging Steel Fabricated by Selective Laser Melting

DOI

10.2991/icadme-16.2016.66How to use a DOI?

Keywords

Additive manufacturing, Selective laser melting, 18Ni-300 alloy, Tensile property.

Abstract

High-strength 18Ni-300 maraging steel parts were fabricated by selective laser melting (SLM) additive manufacturing. Aging treatment at 490 ºC for 6 hours was applied for improving the mechanical properties of SLM fabricated parts. The microstructure and properties of the as-fabricated SLM 18Ni-300 parts were carefully characterized and analyzed. The results show that the relatively low surface roughness, with 4.16 m for horizontal surface and 4.79 m for vertical surface, certified the high accuracy of forming process. The almost fully dense microstructures of the as-fabricated SLM specimens were consisted of sub-micron dendritic cellular structures for horizontal cross-section and elongated acicular structures for vertical cross section. Due to precipitated-phase strengthening, the hardness increased from 35~36 HRC to 51~55 HRC after heat treatment. Meanwhile, the ultimate tensile strength (Rm) increases from 1165 MPa to 2014 MPa, which increased by about 73%; while the break elongation ( ) was reduced from 12.44% to 3.28%, owing to the increased embrittlement caused by the heat treatment. The substantial plastic deformation and dispersively distributed dimples in the fracture morphologies indicated a ductile fracture of as-fabricated tensile specimens, while the age-hardened tensile specimen encountered with a main fracture mode of brittle fracture.

Copyright

© 2016, the Authors. Published by Atlantis Press.

Open Access

This is an open access article distributed under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).

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TY  - CONF
AU  - Chaolin Tan
AU  - Kesong Zhou
AU  - Xin Tong
AU  - Yushan Huang
AU  - Jing Li
AU  - Wenyou Ma
AU  - Fuhai Li
AU  - Tongchun Kuang
PY  - 2017/07
DA  - 2017/07
TI  - Microstructure and Mechanical Properties of 18Ni-300 Maraging Steel Fabricated by Selective Laser Melting
BT  - Proceedings of the 2016 6th International Conference on Advanced Design and Manufacturing Engineering (ICADME 2017)
PB  - Atlantis Press
SP  - 404
EP  - 410
SN  - 2352-5401
UR  - https://doi.org/10.2991/icadme-16.2016.66
DO  - 10.2991/icadme-16.2016.66
ID  - Tan2017/07
ER  -