Preparation of 24CrNiMoY alloy steel with high strength and toughness by selective laser melting

ABSTRACT

24CrNiMoY alloy steel with high strength and toughness was prepared by selective laser melting (SLM) technology. The microstructure and mechanical properties of alloy steel samples prepared by SLM using different laser energies were studied. The results showed that with increasing energy density, the internal defects of the sample first decreased and then increased, and the hardness and tensile properties also showed a trend of increasing at first but decreasing afterwards. When the energy density was 100.7 J/mm³, the alloy steel sample has the fewest defects and the highest hardness (391.2 HV_0.2). The tensile strength and impact toughness also reached the best state: the tensile strength was 1252.83 MPa, the yield strength was 1041.62 MPa, the elongation to fracture was 12.89%, and the impact toughness was 65.7 J. The microstructure of 24CrNiMoY alloy steel prepared by SLM is mainly composed of fine lath martensite, which has good strength and toughness.

KEYWORDS:

• Selective laser melting
• high-speed rail brake disc
• 24CrNiMoY alloy steel
• strength and toughness

Disclosure statement

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

Additional information

Funding

This work was financially supported by the National Key R&D Program of China (2016YFB1100201), the Green Manufacturing System Integration Project of the Industry and Information Ministry of China (2017-53), and the Shenyang important scientific and technological achievements transformation project (20-203-5-6), The open competition mechanism to select the best candidates to lead key research projects in Shenyang city (22-101-0-16).

Notes on contributors

Miao Sun

Miao Sun (1989-), female, Doctor, mainly engaged in the research of material science and engineering.

Suiyuan Chen

Suiyuan Chen (1964-), male, Doctor, Professor, mainly engaged in the research of material science and engineering.

Mingwei Wei

Mingwei Wei (1990-), male, Doctor, mainly engaged in the research of material science and engineering.

Jing Liang

Jing Liang (1973-), female, Doctor, Associate Professor, mainly engaged in the research of material science and engineering.

Changsheng Liu

Changsheng Liu (1963-), male, Doctor, Professor, mainly engaged in the research of material science and engineering.

Mei Wang

Mei Wang (1973-), female, Bachelor, mainly engaged in research on laser additive manufacturing technology.