High resolution imaging of martensitic all-weld metal

ABSTRACT

Martensitic steel welds show promising results regarding their strength while they may tend to be brittle. As martensite is a quite complex microstructure, high resolution techniques like electron backscatter diffraction (EBSD) and atom probe tomography (APT) are valuable tools for an in-depth characterisation. In this study, the average block size and misorientation distribution of martensitic all-weld samples were evaluated with EBSD. A lower carbon content led to a smaller block size and consequently a higher toughness of the all-weld sample. Furthermore, APT revealed a concentration fluctuation of the main alloying elements and particles with a high carbon content. It is discussed how these methods can be used in the future to design the microstructure to achieve optimum properties.

KEYWORDS:

• Filler materials
• weld metal
• toughness
• strength
• microstructure
• martensite
• electron backscatter diffraction
• atom probe tomography

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The K-Project Network of Excellence for Metal JOINing is fostered in the frame of COMET – Competence Centers for Excellent Technologies by BMWFW, BMVIT, FFG, Land Oberösterreich, Land Steiermark, Land Tirol and SFG. The programme COMET is handled by FFG (Österreichische Forschungsförderungsgesellschaft).