变工况下钢厂转炉支承螺栓断裂机理分析

Fracture mechanism analysis of steel mill converter supporting bolt under variable working conditions

在变工况条件下,炼钢厂转炉在运行过程中支承螺栓容易发生断裂,针对这一问题,以某钢厂130 t转炉为例,对不同工况下炼钢转炉支承螺栓的断裂机理进行了研究。首先,推导了转炉的倾动力矩方程,采用MATLAB计算不同倾动角度下转炉倾动力矩,得到了倾动力矩曲线,从而准确计算出了不同工况下支承螺栓的载荷;然后,采用有限元方法对支承螺栓进行了建模,对最大受力情况下的支承螺栓及其销轴进行了力学分析;最后,对支承螺栓结构进行了优化改进,并对优化后的支承螺栓进行了性能验算。研究结果表明:转炉在旋转至65°时,支承螺栓的受载最大,出钢口对侧螺栓过度圆弧处最大等效应力接近材料屈服强度极限;所采用分析方法可为后续定量增大支承螺栓安全系数提供依据,以确保转炉在不做较大结构修改前提下的安全运转。

Aiming at the problems such as the fracture of the supporting bolts during the operation of the converter in a steelmaking plant with variable working conditions,the fracture mechanism of the supporting bolts in the steelmaking converter under different working conditions was studied with a 130 t converter being taken as an example.Firstly,the converter tilting moment equation was derived,the MTALAB was used to analyse and calculate the converter tilting moment at different tilting angles,and the tilting moment curve was obtained so that the load of the supporting bolt under variable working conditions could be accurately calculated.Then,the finite element method was used to model the support bolts,and the mechanical analysis of the support bolts and their pins under the condition of maximum force was carried out.Finally,the support bolt structure was optimized and improved,and the performance of the optimized supporting bolt was checked.The results show that the supporting bolts are the most loaded when the converter rotates to 65°.The maximum equivalent stress value at the excessive arc of the bolts on the opposite side of the tap hole is close to the yield strength limit of the material.The adopted analysis method provides the basis for the subsequent quantitative increase of the safety factor of the supporting bolts,so as to ensure the safe operation of the converter without major structural modifications.