不锈钢高强度螺栓受力性能试验研究

鉴于国内尚无对不锈钢高强度螺栓性能和扭矩系数的相关研究，且螺栓存在产品规格不全、使用不规范等问题，对7种不同材料、不同生产工艺的不锈钢高强度螺栓开展了全面的力学性能试验，获得了各种螺栓的几何参数、化学成分、材料力学性能以及硬度等关键参数，建立了不同种类不锈钢高强度螺栓材料的本构模型，确定了不锈钢高强度螺栓的预拉力值。开展了不锈钢高强度螺栓的扭矩系数试验，发现不锈钢螺栓在紧固过程中发生咬死现象，采用以二硫化钼为主要成分的润滑剂可有效解决螺栓咬死问题。试验结果表明：采用高效润滑剂减摩，使得不锈钢螺栓的扭矩系数接近现有碳钢高强度螺栓扭矩系数0.11~0.15的要求。参考JGJ 82—2011《钢结构高强度螺栓连接技术规程》，提出了不锈钢高强度螺栓的施工预拉力要求，确定了不锈钢高强度螺栓的施工扭矩。

Experimental study on mechanical properties of stainless steel high strength bolts

The research on mechanical properties and torque coefficients of stainless steel high strength bolts have not been reported domestically. The specifications of bolt products are incomplete and the applications are not regulated. The comprehensive mechanical performance tests on seven kinds of stainless steel high strength bolts with different materials and producing processes were carried out in this paper. The geometric parameters, chemical compositions, material properties and hardness were obtained. Furthermore, the constitutive models of different stainless steel bolts were built and the tightening forces were determined. The torque coefficient tests of stainless steel high strength bolts were also performed and the thread galling was commonly observed during the tightening processes. When using the lubricants with MoS2 as the main component, the galling problems could be solved effectively. The test results reveal that when using the high-efficiency lubricant, the torque coefficients of stainless steel bolts are nearly in the range of 0.11-0.15, which is the requirement for carbon steel high strength bolts. Based on the current specifications JGJ 82—2011 for carbon steel high strength bolts, the construction tightening forces and torques for stainless steel high strength bolts were finally determined.