Feasibility study of welding dissimilar Advanced and Ultra High Strength Steels

Laser welding of modern automotive high strength steels

The paper demonstrates the correlation between the chemical composition of steel grades and the hardness as well as the formability of laser welds generated with modern automotive high strength steel grades. At the very low heat input of industrial laser welding and the resulting extremely high cooling rate, the weld hardness is fully controlled by the carbon content of the base materials and n...

High-Strength Bainitic Steels

With careful design, mixed microstructures consisting of fine plates of upper bainitic ferrite separated by thin films of stable retained austenite have exhibited impressive combinations of strength and toughness in highsilicon bainitic steels. The silicon suppresses the precipitation of brittle cementite leading to an improvement in toughness. The essential principles governing the optimisatio...

High Strain Rate Characterization of Advanced High Strength Steels

Laser-Ultrasonic Monitoring of Metallurgical Transformations in Advanced Ultra-High Strength Steels

This paper discusses the use of laser-ultrasonics to monitor the metallurgical transformations of advanced high-strength steels. In this technique, acoustic waves are generated and detected in the material by use of lasers. The ultrasonic velocity can sense the austenite formation/decomposition in real time. Unlike dilatometric measurements the ultrasonic velocity measurements show little influ...

Investigation of structural changes in resistance spot welding of advanced high strength steel DP590

The structural and hardness developed in advanced high-strength steel DP590 have been investigated with the help of optical microscopy and scanning electron microscopy on resistance spot welded specimens. The hardness diagram of the weld sections was prepared by microhardness test and the temperature peak and heat distribution were simulated by menas of the Abaqus software. The results show tha...