A team of researchers from Japan's National Institute for Materials Science (NIMS) has announced a significant advancement in metal 3D printing, improving the durability of heat-resistant steel by utilizing a method known as laser powder bed fusion (LPBF).
The research indicates that LPBF has extended the creep life of heat-resistant ferritic steel, specifically modified 9Cr-1Mo steel, by over ten times compared to traditional manufacturing techniques. This steel is commonly employed in thermal power plants.
In experiments, the researchers conducted creep tests at 650°C and 100 MPa of pressure over a period of 10,000 hours. While conventional heat-treated steel ruptured within 400 to 800 hours, the LPBF specimens displayed no signs of failure even after extensive testing.
The unique durability of LPBF steel is attributed to its microstructure, which differs significantly from that of traditionally heat-treated steel. The rapid cooling during the LPBF process produces a high-temperature δ-ferrite phase, enhancing the material's ability to withstand extreme conditions.
Ongoing testing aims to further evaluate the material's limits, with researchers targeting a creep rupture strength assessment at 100,000 hours. The implications of this research could lead to safer and more durable components in various industries, including power generation and aerospace.
As the team continues to explore the potential of LPBF technology, the findings may pave the way for the broader adoption of advanced manufacturing techniques that can produce complex shapes while enhancing material performance.