钢帘线用72C盘条的微观组织与力学性能研究

Microstructure and Mechanical Properties of 72C Steel Wire Rod for Steel Cord

对国内外不同厂家钢帘线用72C盘条的化学成分、微观组织和力学性能进行了分析。结果表明,国内外盘条横截面显微组织均是由索氏体+微量先共析铁素体+少量珠光体组成。由于国内B盘条和国外C盘条的珠光体片层间距较小,导致其抗拉强度和断面收缩率均高于国内A盘条。国内外盘条横截面均无明显中心偏析现象,但国内A盘条中有害元素硫和磷含量以及夹杂物含量相对较高。以国内A盘条为原料生产小规格的钢帘线时,断丝率较高,且在捻制断口上发现脆性夹杂。实践表明,夹杂是生产小直径钢帘线捻制过程中影响断丝的主要因素。

The chemical composition, microstructure and mechanical properties of domestic and foreign 72C steel cord were analyzed. The results show that the cross sectional microstructure of all three wire rods consists of sorbite and minor pro-eutectoid ferrite and a few pearlite. The tensile strength and reduction of area of domestic B and Foreign C were higher than that of the Domestic A wire rods, due to their smaller interlamellar spacing. There was no found central segregation in the cross section of all three wire rods, but the content of harmful elements sulfur and phosphorus and inclusion in the Domestic A wire rod was relatively higher. The more higher wire breaking rate was found in the process of small diameter steel cord used Domestic A wire rods as the material and the brittle inclusion was clearly observed on the twisting fracture. The operation practice shows that the inclusion is the main factor for affecting the wire breaking for the production of small diameter steel cord.