HTR-PM螺栓拉伸机无测量杆螺柱预紧力标定试验研究

为了解决高温气冷堆示范工程（HTR-PM）无测量杆螺柱预紧力的控制问题，保证反应堆一回路压力边界的法兰密封，需要对无测量杆螺柱的预紧力进行标定。以HTR-PM中 M56无测量杆螺柱为例，采用液压拉伸机对其进行标定试验，找到螺栓拉伸机拉伸预紧力与螺柱残余预紧力的关系曲线；分析了螺栓拉伸机拉伸前后导致螺柱残余预紧力下降的原因，再通过材料力学本构关系，建立了螺栓拉伸机拉紧力与螺柱回弹后残余预紧力的理论关系式。结果表明，试验获得的螺柱联接体系中的残余预紧力及螺母旋紧前的预紧力关系式都与理论分析比较接近；螺栓拉伸机相同出力下，实际设备管嘴法兰螺柱的残余预紧力会比标定值大，但这更有利于法兰面的密封。 

Pre-Tightening Force Calibration Test Research for Stud without Measuring Rod of HTR-PM

In order to control the final pre-tightening force of the stud without measuring rod in the high temperature gas cooled reactor Pebble Module (HTR-PM) and ensure the sealing of the reactor primary circuit pressure boundary, it is necessary to calibrate the pre-tightening force of the stud. Taking the M56 stud without measuring rod as an example, the calibration test was carried out with a bolt tensioner, and the relation curve between the pre-tightening force and the final pre-tightening force of the stud was found. The final pre-tightening force on the stud was smaller than the pre-tightening force of the bolt tensioner when the nut was tightened. The reason of the force decreasing was analyzed. The relation formula between the pre-tightening force and the final pre-tightening force of the stud was established through the constitutive relation theory of material mechanics. It was shown that the final pre-tightening force and its relation between the pre-tightening force obtained from the test were close to the theoretical analysis results. Under the same output force of the bolt tensioner, the final pre-tightening force of the actual equipment nozzle flange studs will be larger than the calibrated value, but this is good for the sealing.