Secondary Carbide Dispersion Structure
Secondary carbide dispersion structure consists of finely distributed carbides in a martensitic or ferritic matrix. It increases hot strength and improves deformation behavior.
Physical–Chemical Mechanism
Secondary-carbide dispersion structure forms when fine secondary carbides are evenly distributed in the matrix. These carbides precipitate during welding or through targeted tempering and they coarsen. They act as obstacles to crack growth and thus improve material behavior.
Metallurgical Relevance & Welding Risks
This structure raises the hot strength and improves the formability of the steel. It reduces susceptibility to hot cracking and improves toughness under load. However, if handled wrong or if the carbide content is too high, hardness can increase, which can cause damage during forming.
Shop Practice & How-Tos
To get a secondary-carbide dispersion structure, the steel should be tempered with the right carbide content (about 0.5 to 1.0 %). Welding processes should be run under controlled temperatures and times to make sure the carbides are finely distributed. If hardness is high or cracks are likely, check the material before use and temper it if needed.