Thermoboost^®

Thermoboost^® is a temporary coating that is applied to AluminumSilicon (AlSi) coated steels to increase the heating rate of ArcelorMittal’s family of press hardened steels. The black waterbased coating is applied onto one side of the AlSi coated coil. 

Thermoboost^® is a proven technology that improves both product and process performance:

• Reduced heating times in standard hot stamping furnaces
• Expanded heating process windows for a wider range of gauge combinations including patches or tailor welded blanks
• Validated complete removal of the paint after heating
• Reduced geometrical distortions during blank heating
• Reduced H₂ intake
• Equivalent part properties to the standard Usibor^®1500 AS, demonstrating equivalent welding behavior, corrosion resistance, and adhesive bonding performance
• Fully compatible with current hot stamping lines

When the Thermoboost^® coated blank passes through the hot stamping furnace at the austenitizing temperature, the Thermoboost^® coating completely decomposes leaving no Thermoboost^® coating residue. The heating time can be reduced by ~35% compared to standard AS150 coated Usibor^® and Ductibor^®.

Geometrical distortion in the furnace can result from uneven heating rates in the blank due to different thicknesses heating at different rates. Thermoboost^® applied to the patch increases the heating rate of the thicker portion of the blank, resulting in more uniform heating rates throughout the blank, eliminating the cause of distortion.

ArcelorMittal Multi Part Integration™ concepts will benefit from strategically using Thermoboost^® coating on thicker parts to tailor the multiple gauge blank for overall uniform heating in the hot stamping process resulting in improved processing windows and a uniform microstructure (coating and steel base).

Uniform heating of laser welded blanks with thicker patched areas can be achieved when the patch is coated with Thermoboost^®. When Thermoboost^® is applied on the patch, the increased heating rate of the thicker area enables faster overall heating and a larger process window.

Example of a patched double door ring

In this example a double door ring has thicknesses ranging from 1.00 mm to 3.8 mm in the patched area. The process window for all thicknesses to reach the right AlSi coating alloying is narrow. With Thermoboost^® applied on the patch the increased heating rate of that thick area enables faster heating and a larger process window.