Tag: steel

Cheaper, greener steel for the automotive industry

Cheaper, greener steel for the automotive industry

Finnish researchers develop new composition, manufacturing process for producing stronger steel

Automakers today use a special type of steel (called Advanced High-Strength Steel, or AHSS) in components critical to driver and passenger safety, such as safety cages and bumpers. These parts of the car are designed to absorb collision forces so that less impact is transferred to occupants.

Researchers in Finland have developed not only a new composition for this type of steel but also a new manufacturing process that produces a stronger steel while also making it cheaper and more environmentally friendly. Their findings are published in the journal Materials & Design.

“We wanted to know: can we make steels that are two or three times stronger than current formulations, so we can reduce the amount of steel required and lower the overall weight of a vehicle?”  says Roohallah Aliabad, a researcher at the Microstructure and Mechanisms research group (Centre for Advanced Steels Research) at the University of Oulu. “A byproduct of this research is reducing greenhouse gas emissions. When you reduce the weight of cars, you are indirectly contributing to that goal.”

Aliabad and his colleagues are investigating compositions and processing routes that use manganese as an alloying element. Manganese is significantly less expensive than chromium and nickel, which are traditionally used in steel alloys. The team found that, by tailoring the microstructure of their steel, they could create an ultra strong, non-uniform microstructure (controlled heterogeneity) that contains two types of austenite, a form of iron.

Read more on the CLS website

Image: Roohalah Aliabad, Centre for Advanced Steels Research, University of Oulu (Finland)

X-rays make 3D metal printing more predictable

X-rays make 3D metal printing more predictable

Insights into the microscopic details of 3D printing gained using the microXAS beamline of the Swiss Light Source SLS could propel the technology toward wider application.

Researchers have not yet gotten the additive manufacturing, or 3D printing, of metals down to a science completely. Gaps in our understanding of what happens within metal during the process have made results inconsistent. But new research could grant a greater level of mastery over metal 3D printing.

Using powerful x-rays generated by the Swiss Light Source SLS and Argonne National Laboratory’s Advanced Photon Source, researchers at Paul Scherrer Institute PSI, the National Institute of Standards and Technology (NIST), KTH Royal Institute of Technology in Sweden and other institutions have peered into the internal structure of steel as it was melted and then solidified during 3D printing. The findings, published in Acta Materialia, unlock a computational tool for 3D-printing professionals, offering them a greater ability to predict and control the characteristics of printed parts, potentially improving the technology’s consistency and feasibility for large-scale manufacturing. 

“So-called operando measurements with x-rays enable us to capture what is really happening to the microstructure during a rapid process such as printing.” said Steven Van Petegem, senior scientist at PSI, who led the experimental work performed at the SLS using the microXAS beamline.

Read more on the PSI website

Image: Researchers used high-speed X-ray diffraction to identify the crystal structures that form within steel as it is 3D-printed. The angle at which the X-rays exit the metal correspond to types of crystal structures within.

Credit: H. König et al. via Creative Commons (https://creativecommons.org/licenses/by/4.0), adapted by N. Hanacek/NIST