Brazil develops a new high-temperature laser welding method to improve the performance of high-strength steel and reduce weight

According to foreign media reports, Brazilian researchers have developed a new high-temperature laser welding method that can improve the application of advanced high-strength steel in the automotive and aerospace fields. However, some high-strength alloys are usually brittle when performing welding, hot pressing, and forming processes.

This technology was developed by de Lima, which performs induction heating of 22MnB5 steel plate to 450°C and waits 10 minutes before laser welding. 22MnB5 is the most promising advanced high-strength steel in the current hot stamping and forming process. This material is used in automobile structural parts and safety parts. The mechanical properties of the finished parts are extremely high. Compared with the traditional cold-formed steel, it 30-50% weight reduction can be achieved.

After the welding operation is completed, the high temperature of the steel plate can be maintained for 10 minutes to form a bainitic structure. Metallurgical experts have discovered that under certain conditions, such bainite flake microstructures can be formed in steel, which can produce hard and reliable welds. It is worth mentioning that the material can exhibit high yield strength and tensile strength (tensile strengths).

According to analysis, the steel plate welded at high temperature contains a bainite structure, and its hardness is much higher than that of the steel plate welded at room temperature. The latter is martensite. The yield strength and tensile strength of this microstructure are higher than that of bainite. Bad. The team also demonstrated the resilience of the welded steel plate at high temperatures.

The high temperature welding allows the sample to show the microstructure of bainite and austenite grains. According to de Lima, this technology can be used in manufacturing to improve the laser welding level of high-strength steel and ultra-high-strength steel.

The automotive industry uses laser welding to join steel blanks and body stamping structural parts, such as pillars, beams, and car frames. Compared with traditional welding technology, laser welding is faster and more reliable.

Although the research is still in its early stages, bainitic steel is expected to be an excellent shielding material and armoring material.

de Lima is currently participating in a new research project, which is supported by the Sao Paulo Research Foundation (FAPESP) in Brazil, which aims to verify the feasibility of the technology in Brazilian factories. In addition, laser welding will also be applied to maraging steel.