Formability of high-strength, low-alloy steel sheet: shearing

Abstract

The effect of variation in blade-to-blade clearance (5·0–35·0 × 10⁻² mm) on the symmetrical shearing of a high-strength, low-alloy (HSLA) steel and its relationship to hardness, shear strain, fracture behaviour, burr height, burnish depth, and fracture angle have been studied. The maximum shear strain is found to be inversely proportional to the clearance, for increasing the clearance introduces a greater tensile component and an increasing propensity [or ductile fracture; additionally, with increasing clearance the volume of the deformed region increases. Fracture occurs where the rate of change of hardness is at a maximum, and fracture angle increases with increasing clearance, whereas burnish depth and bottom-burr height are inversely related to clearance. Alternate shear and ductile fracture zones are observed on the sheared surfaces. Finally, certain practical recommendations are made.