高强度缆索锚具用钢强韧化热处理工艺研究

Technology Research on Strengthening and Toughening Heat Treatment of High Strength Cable Anchorage Steel

40Cr、42Cr Mo和40Cr Ni Mo A钢被广泛应用于桥梁拉索锚具的制造,为了指导桥梁拉索锚具的设计和安全选材,本文研究了热处理工艺对三种常用钢材组织和力学性能的影响。研究结果表明:42Cr Mo和40Cr Ni Mo A钢的淬透性均优于40Cr钢。当大规格锚具壁厚超过40 mm时,锚具设计时建议采用42Cr Mo和40Cr Ni Mo A钢。由于材料淬透性的影响,抗拉强度、屈服强度及硬度随壁厚的增加而降低。设计大规格锚具计算强度时,需根据力学性能的分布规律进行修正,可取两边强度的平均值进行推算。

40Cr, 42CrMo and 40CrNiMoA steels are widely used in manufacturing the large-size cable an- chorage of bridge. In order to guide the design of the cable anchorage and material selected safely, the effect of heat treatment processes on microstructure and mechanical properties of above three steels are in- vestigated in this paper. The results show that the hardenability of both 42CrMo and 40CrNiMoA steel is superior to that of 40Cr steel. When the thickness of the large-size cable anchorage surpasses 40 mm, 42CrMo and 40CrNiMoA steels be recommended for designing the cable anchorage. The tensile strength, yield strength and hardness reduce with the increase of thickness of the cable anchorage due to the effect of hardenability. Therefore, the strength is corrected according to the regularitues of distribution of mechani- cal property as calculating the strength of the large-size cable anchorage in design, and calculated by the average strength between surface and core.