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Organization
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Jiangsu Baogang Precision Steel Wire Co., Ltd.
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E-mail
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guj@baosteel.com
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Challenge (Project)
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Reducing breakdown rate of UT class steel cord stranding
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Description
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When moving from the previous procedure of 5.5mm rod to the next procedure of drawing of 0.3mm or smaller single wire, extra high strength steel wire has higher compression ratio, higher work hardness and lower plasticity than high strength (ST, HT) wire. When going through the false twister, torsional deformation of twist reaches a point of plasticity due to large amount of secondary twisting. As such wire tends to experience defects such as crack and extends rapidly until it breaks.
As residual stress unavoidably exists during wire twisting and saturated residual torsion increases with the increase of strength but the decrease of diameter, extra high strength cord shows very high saturated torsion due to small diameter and high strength of a single wire. To eliminate residual torsion, speed of false twister needs t be accelerated for production of per unit length of cord. As a result, wire reaches plastic deformation stage quickly and breaks.
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Technical Parameters/Requirements
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1. How to overcome defects of high work hardness and low plasticity of extra high strength cord during drawing?
2. How to reduce the speed of false twister by eliminating residual stress of wire?
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Profile (existing facilities, equipment and products)
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The company specializes in the production of high-tech and high value-added precision products including cut wire and steel cord. It has completed 50kt/a phase I construction, including 5kt/a cut steel and 45kt/a steel cord. Prevailing and proven equipment has been selected for the overall production process to ensure quality.
The company intends to expand its capacity to 150-200kt/a in the long run and becomes the largest steel cord manufacturer in terms of unit size.
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