Thermographic detection of defects for SMEs
During the galvanizing process of steel parts (immersion in a bath with molten zinc) there is a risk of explosion of water that remains captured in cavities. This risk is high for small series and first trials. An infrared camera may help to identify the areas of risk, but SMEs do not have the expertise to apply these techniques. In this project SMEs were instructed in how to apply the technique and how to analyze the results.
• The objective is to galvanize a thin layer of zinc to metal surfaces via thermal freezing. In this process different kinds of baths are used. There is a major risk that water remains present in different cavities of the metal object.
• To reduce the risk of the presence of water, holes are drilled at specific locations. However, small amounts of water or enclosed air in cavities may lead to unwanted situations in thermal galvanizing.
• Determine the feasibility of the use of thermal infrared cameras for visualizing water filled cavities or enclosed cavities.
• Design and optimize potential system concepts for early semi-automatic detection of cavities based on thermal infrared cameras.
• Several concepts were proposed consisting of single hand-held as well as automated multi-sensor systems.
• Successful demonstrations were given with the first type of concept at several galvanizing companies showing potential for a safer process.
Syntens and TNO