Abstract: The cross section and longitudinal section microstructure morphology of two different Si contents hot-rolled wire rods were observed using scanning electron microscopy and energy spectrum （EBSD） instruments. The tensile properties of the hot-rolled wire rods were tested using a universal testing machine. The results show that with the increase of Si content， the undercooling of pearlite transformation increases， and the size of pearlite colony and pearlite interlamellar spacing in hot-rolled wire rods decrease.The Si element causes the Mn element to segregate in the cementite， increasing its stability and reducing the spheroidization of the cementite lamellae. The Si element weakens the texture strength of the pearlite in the transverse and longitudinal sections of the wire rod， leading the pearlite structure more uniform and the orientation more random. The Si element can greatly improve the strength of hot-rolled wire rods and finished steel wires， while slightly improving plasticity. The tensile strength of low Si wire rod is 1134 MPa， and the uniform elongation is 7.1%； The tensile strength of high Si wire rod is 1263 MPa， and the uniform elongation is 7.3%. The tensile strength of the low Si wire is 1937 MPa， and the uniform elongation is 2.2%； The tensile strength of the high Si wire is 2106 MPa， and the uniform elongation is 2.3%.

Key words: Cable Steel Wire Rope, Hot-Rolled Wire Rod, Si Element, Pearlite, Microstructure and Mechanical Properties

摘要： 利用扫描电镜和能谱（EBSD）仪器对两种不同Si含量的热轧盘条的横截面和纵截面的组织形貌进行观测，并用万能试验机测试热轧盘条的拉伸性能，结果表明：随着Si含量的增加，珠光体转变的过冷度增加，热轧盘条的珠光体团尺寸和珠光体片间距减小。Si元素使Mn元素在渗碳体中偏聚，增加了渗碳体的稳定性，减小了渗碳体片层的球化倾向。Si元素使盘条横、纵截面珠光体的织构强度减弱，珠光体组织更加均匀，取向更加随机。Si元素能大幅度提升热轧盘条和成品钢丝的强度，小幅度提升塑性。低Si盘条的抗拉强度为1134 MPa，均匀伸长率为7.1%；高Si盘条的抗拉强度为1263 MPa，均匀伸长率为7.3%。低Si钢丝的抗拉强度为1937 MPa，均匀伸长率为2.2%；高Si钢丝的抗拉强度为2106 MPa，均匀伸长率为2.3%。

关键词: 缆索钢丝绳, 热轧盘条, Si元素, 珠光体, 组织性能