对Ⅲ型棉包钢丝力学性能与生产工艺的探讨

根据YB T 5 0 3 3— 1993对棉包钢丝的强度要求 ,对Ⅲ型棉包钢丝的安全系数进行了计算 ,并与美国棉包钢丝保险系数 ( 1.5 82～ 1.90 3 )进行对比 ,结果显示我国棉包钢丝的安全系数 ( 1.0 2 5～ 1.2 3 6)相对较小。对Ⅲ型棉包断丝原因进行分析 ,认为断丝多发生在套扣之处是由钢丝的塑性、韧性偏低造成的。建议用于棉花含水率大于5 %的棉包钢丝的抗拉强度为 4 0 0～ 4 60MPa,延伸率≥ 18%,弯曲≥ 15次 ,以便提高安全系数和韧性。给出棉包钢丝生产的热处理工艺参数和所生产的钢丝的力学性能 ,结果显示所生产的钢丝性能良好。

Inquire into Production Technology and Mechanical Properties of Ⅲ-type Cotton Baling Wire

To calculate the safe coefficient of Ⅲ type cotton baling wire according to strength requirement of YB/T?5033-1993 on cotton baling wire,and the safe coefficient (1.582～1.903) of American cotton baling wire is compared.The result shows that the safe coefficient(1.025～1.236)of cotton baling wire of our country is less correspondingly.The cause for Ⅲ type cotton baling wire breaking is analyzed.It is considered that wire breaking which usually appears at knot is due to low plasticity and toughness of steel wire.It is suggested that the cotton baling wire used for moisture content of cotton more than 5% should have tensile strength 400～460?MPa,percentage elongation≥18% and bend≥15 times so as to improve safe coefficient and toughness.The heat treatment process parameters for producing cotton baling wire and the wires'mechanical properties are given,the results show that the properties of wires produced by the process are good.