高温后结构钢力学性能试验

为了研究结构钢高温后材料力学性能变化规律,对Q 235结构钢加热至不同高温,再经不同方式冷却后进行了力学性能试验。试验表明:结构钢经不同高温冷却后,有显著热变色反映;高温后的弹性模量、屈服强度、抗拉强度和断后伸长率等力学性能变化程度主要与曾经历的最高温度和冷却方式有关。根据试验结果,编制了高温后钢材热变色图谱,提出了高温后结构钢的屈服强度、抗拉强度计算公式,对高温后弹性模量的取值提出了建议。研究成果可供火灾后钢结构损伤评估和加固分析时参考。

Experimental investigation into mechanical properties of steel post high temperatures

To invest igate the law s of variat ion o n the mechanical pro pert ies of st ructural steel at po st high temperatures, tensile tests w ere conducted af ter Q235 steel w as cooled dow n from differ ent high temperatures. T he tests indicate that the st ructural steel pr esent s thermochr omism after cooling dow n f rom dif ferent high temperatures, that the variat io n law s of the y ield st rength, the tensile st reng th, the elast ic modulus and the elong at ion percentag e are most ly af fected by endured different high temperatures and different co oling pat terns. Based o n the experimental result s, the thermochromism proper ties at las and the calculatio n formula o f yield st reng th and tensile st rength w ere pro posed as w ell as the sug gest ions of reduced elastic modulus of the steel post hig h temperatures. The conclusio ns supply r eferences for the evaluation of damag e and the reinforcement o f steel st ructure post fire