A team of researchers from Japan’s National Institute for Materials Science (NIMS) has made a breakthrough in metal 3D printing, dramatically improving the durability of heat-resistant steel.
By using a technique called laser powder bed fusion (LPBF), they extended the steel’s creep life by over 10 times compared to traditional methods.
Their findings, published in the journal Additive Manufacturing, could have major implications for industries that rely on high-temperature, high-pressure materials, such as power plants.
LPBF is a cutting-edge 3D printing method where metal powder is layered and melted with a laser to form solid metal structures.
By stacking these layers, the process builds intricate 3D components that would be difficult or impossible to create using conventional techniques.
To test LPBF’s potential, the researchers created specimens from a heat-resistant ferritic steel known as modified 9Cr-1Mo steel, commonly used in thermal power plants.
They then conducted creep tests—experiments that measure how materials deform under high stress and heat—at 650°C and 100 MPa of pressure for up to 10,000 hours (over a year).
The results were astonishing. While steel produced through traditional heat-treatment processes ruptured within 400 to 800 hours, the LPBF-made specimens showed no signs of failure even after 10,000 hours.
Testing is ongoing, with researchers aiming to reach 100,000 hours to fully understand the material’s limits.
So, what makes LPBF steel so durable? The key lies in its unique microstructure. Traditional heat-treated steel forms a tempered martensitic structure, but LPBF’s rapid cooling—estimated at an incredible 1,000,000°C per second—produces a high-temperature δ-ferrite phase.
This distinct microstructure is believed to give LPBF steel its remarkable ability to withstand heat and pressure for extended periods.
The team’s next steps include testing other heat-resistant materials produced through LPBF and generating long-term data to evaluate creep rupture strength at 100,000 hours. These insights will help establish industry standards and encourage the wider adoption of LPBF technology.
This breakthrough has the potential to transform industries that depend on durable, heat-resistant materials. It could lead to safer, longer-lasting components in power plants, aerospace, and beyond. With its ability to create complex shapes and improve material performance, LPBF is paving the way for a new era in manufacturing.
According to the researchers, this is just the beginning. As they continue to push the boundaries of 3D printing and material science, we may soon see a future where high-performance materials like these become the standard across multiple industries.
