Numerical and experimental investigation of notch-induced high-speed precise shearing of 42CrMo bar

• DOI: 10.1177/0954406220964509
• Publication Date: 2020-10-07T07:01:00Z
• Authors: Yuanzhe Dong; Yujian Ren; Hong Jiang; Shuowen Zhang; Shengdun Zhao
• Keywords: Shearing (physics); Fractography; Coalescence (physics)

A notch-induced high-speed precise shearing method was developed for high-strength metal bars, which prefabricated V-shape circumferential notches in batch on the bar surface to make stress concentration, and applied a load complete separation new type of electric-pneumatic counter hammer. The FE simulation experimental tests were conducted; influences loading speed, notch depth, axial clearance analyzed fracture behavior blank quality; microfracture mechanism further investigated. results showed that inhibited plastic distortion obtained high precision chamfered billets, with roundness error 1.34%, flatness 0.34 mm, incline angle 0.87°. Besides, effectively reduced Max. impact force energy. fractography revealed that: notched bar, cracks initiated from thin extrusion layers at bilateral-notch tips, micro intrusion top-notch tip. predominant involves microvoid coalescence forming quasi-parabolic dimples along shear stress.