Secondary precipitate phase
Secondary precipitate particles are finely dispersed particles that form in the matrix during heat treatment or loading. They block dislocation movement and increase the steel's hot strength.
Physical-Chemical Mechanism of Action
Secondary precipitates form when chemical compounds or elements come out of the matrix. This can happen through diffusion processes, precipitation, or other thermal reactions. The particles can be made of different materials, e.g. silicon compounds or sulfur compounds.
Metallurgical Relevance & Welding Risks
These phases affect the steel's mechanical properties, especially its hot strength and toughness. Too many secondary precipitates can lead to increased hardness and reduced durability. This can cause cracking or wear problems in the weld joint, especially under high stress.
Workshop Practice & Instructions
To control the formation of secondary precipitates, heat treatment parameters like temperature and time must be followed precisely. For certain steel grades, it's important to ensure enough cooling time after welding to minimize the formation of these phases. Under high stress or for special applications, a specialized heat treatment may be needed.