Evaluation of Deformation Behavior of HSLA-100 Steel Using Magnetic Hysteresis Technique

The magnetic properties of heat-treated, copper (Cu)-containing high-strength low-alloy (HSLA-100) steel and the variations of the magnetic properties during tensile deformation were studied. For samples aged at temperatures below 775 K, precipitation of nanosized coherent Cu particles occurred, causing an increase in hardness but a decrease in coercivity. For higher aging temperatures, the Cu precipitates coarsened and then were able to pin domain walls. As a result, magnetic coercivity increased. During tensile deformation of selected heat treated samples, the interaction of dislocations with the coherent and incoherent Cu precipitates influenced the magnetic properties. Systematic variation of coercivity with plastic strain was found for brittle and ductile types of fracture of the materials.