Co微合金化对高级别帘线钢组织与冷拉性能的影响

Influence of Co Micro-alloying on Microstructure and Drawing Properties of High-grade Tire Cord Steels

为了减轻高级别帘线钢晶界渗碳体(GBC)的析出、提高其强度和冷拉性能,研究了Co微合金化80,100级帘线钢的显微组织及性能变化规律。用扫描电镜(SEM)观测了不同Co含量试样的显微组织形貌、GBC析出及珠光体片间距;用力学实验机测量了热加工及冷拉拔后的力学性能。结果表明:自然冷却时,Co微合金化可显著细化珠光体团尺寸;随Co量增加,抗拉强度增加,面缩率降低,但GBC变得严重。盐浴处理后,GBC受到抑制,冷拉加工硬化率得到提高。

The law of microstructures and properties of 80 and 100-grade tire cord steels with Co micro-alloying were investigated,in order to alleviate the precipitation of grain boundary cementite（GBC） and enhance their strengths and cold drawing properties.The microstructure,precipitation of GBC and the interlamellar spacing of pearlite of specimens with various Co contents were observed and measured using electron scanning microscope（SEM）;the mechanical properties after hot working and cold drawing were measured by means of mechanical testing machines.It was shown that,the Co micro-alloying can decrease greatly the size of pearlite colony on condition of natural cooling;the ultimate strength were increased and the reduction of area decreased but GBC became severe with the contents of Co increasing.GBC were suppressed and cold drawing work hardening rate of high-grade tire cord steels improved after salt bath patenting.