孟宪成, 王勇, 刘雅政. Analysis on Pencil-Tip Shaped Fracture of Cord Steel 72A during Cold Drawing and Improvement of Process[J]. Special Steel, 2009, 30(5): 55-57.
孟宪成, 王勇, 刘雅政. Analysis on Pencil-Tip Shaped Fracture of Cord Steel 72A during Cold Drawing and Improvement of Process[J]. Special Steel, 2009, 30(5): 55-57.DOI:
Un-homogeneity of deformation is the driving force on pencil-tip shaped fracture of cord steel 72A during cold drawing. The coarse proeutectoid ferrite and thicker cementite lamella at center of wire are source of crack during rough drawing; and the crack produced by center segregation often occurs during middle-drawing.With controlling center carbon segregation index of cast billet ≤ 1.1
using ≥ 15℃/s quick cooling process before phase transformation
control- ling cooling at phase transformation zone 600~620 ℃ similar isothermal transformation to obtain proeutectoid ferrite content ≤0.8%
uniform sorbite structure being up to 90%
the pencil-tip shaped fracture of 72A steel wire during straight-line drawing is basically avoided.