Microstructure Adjustment
Microstructure adjustment refers to the controlled modification of the metal structure through thermal and mechanical processes. The goal is to optimize specific material properties.
Physical-chemical mechanism
Microstructure adjustment is achieved by controlling phase composition, grain size, and precipitate distribution in metals. This is done through various thermal (e.g., melting, cooling) and mechanical processes (e.g., deformation).
Metallurgical relevance & risks in welding
Incorrect microstructure adjustment can lead to various problems. Too-hard structures can be prone to cracking, while too-soft structures lose toughness. Proper control of the cooling process is crucial for the quality of the weld and its mechanical properties.
Workshop practice & instructions
To achieve optimal microstructure adjustment, melting and cooling times as well as deformation steps must be precisely controlled. For example, for high-carbon steel, the critical temperature window during cooling should be maintained (t8/5 between 5 and 25 seconds) to obtain a balanced structure. This prevents both the formation of glass-hard martensite and excessive grain growth.