What are the characteristics of cold-drawn steel bars?

Cold drawing involves forcing HPB235 steel bars with a diameter of 6–8 mm through specially designed tungsten alloy die holes, thereby causing plastic deformation in the bars and altering their physical and mechanical properties. After cold drawing of steel bars, lateral compression and longitudinal tension occur, causing slip in the internal lattice, which can increase the tensile strength by 50% to 90% ； Plasticity decreases, while hardness increases. This type of wire that has been cold-drawn is called cold-drawn low-carbon wire. Compared to cold drawing, cold drawing involves only tensile stress, whereas cold drawing involves both tensile and compressive stress. After cold drawing, cold-drawn low-carbon steel wires do not exhibit significant yield behavior. They are classified into two grades: Grade A wires are suitable for use as prestressing tendons, while Grade B wires are suitable for use in welded meshes, welded frameworks, stirrups, and structural reinforcement bars.

Cold drawing of steel bars is a process in which grade I steel bars with a diameter of 6.8 mm are forcefully drawn through specially designed tungsten alloy die holes to become wires of smaller diameter. After cold drawing of steel bars, their hardness increases while plasticity decreases, and the stress-strain behavior no longer exhibits a distinct yield stage.

Cold-drawn steel bars: Cold-drawn steel bars are produced by subjecting hot-rolled steel bars of grades II to III to tension at room temperature to a stress level exceeding their yield point, causing them to undergo certain plastic deformation; after that, the stress is removed and the bars are then subjected to aging treatment. In this way, the plasticity and elastic modulus of the steel bars are reduced, while their yield strength and hardness increase, allowing them to be used directly as prestressed bars.