Microstructure and properties of high power-SLM 24CrNiMoY alloy steel at different laser energy density and tempering temperature

ABSTRACT

In order to improve the manufacturing efficiency, the high power SLM technology was used to fabricate the 24CrNiMoY alloy steel. Effects of laser energy volume density (EVD) and tempering temperature on the microstructure and properties of HP-SLM 24CrNiMo steel were studied. Results show that as the EVD increases, the grows direction of lath martensite microstructure changes to disordered. When EVD is 120 J mm⁻³, the UTS of HP-SLM 24CrNiMoY steel reaches 1125 ± 15 MPa. High UTS is benefit from the fine martensite lath and high density of dislocations. Additionally, tempering treatment can reduce the dislocation density in martensite and promote the precipitation of ϵ carbides. After tempering at 500°C, the EL of HP-SLM 24CrNiMoY steel increased to 7.5% and the product of strength and plasticity increased by 37.8%. This study provides a technical reference for HP-SLM technology to prepare the high-performance 24CrNiMoY alloy steel.

KEYWORDS:

• Selective laser melting
• 24CrNiMoY alloy steel
• high power
• martensite evolution
• mechanical properties

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes on contributors

Miao Sun born in 1989, specialises in 3D laser printing and additive manufacturing technology.

Suiyuan Chen born in 1964, specialises in 3D laser printing and additive manufacturing technology.

Mingwei Wei born in 1990, specialises in 3D laser printing and additive manufacturing technology.

Jing Liang focuses on the application of laser in materials science.

Changsheng Liu pays attention to laser surface treatment technology of metal materials.

Mei Wang is engaged in laser manufacturing and remanufacturing.

Additional information

Funding

This work was financially supported by National Key R&D Program of China (2016YFB1100201), Green Manufacturing System Integration Project of the Industry and Information Ministry of China (2017), Research and development plan for the future emerging industries in Shenyang (18-004-2-26), and Shenyang Achievement Transformation Project (2019).