温度对45钢材料性能影响的试验研究

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中图分类号：TH142.1 文献标志码：A文章编号：1006-0316（2025）08-0023-06

doi ：10.3969/j.issn.1006-0316.2025.08.004

Experimental Study on the Effect of Temperature on the Properties of 45 Steel

PENG Zhaobo，KONG Jinxing，LIU Silai，JIAQi （Instituteof Mechanical Manufacturing Technology，China Academyof EngineeringPhysics， Mianyang 621900， China ）

Abstract ∵ Temperature is an important factor affecting the mechanical and thermal properties of 45 steel. In this paper，the efect of temperature on the properties of 45 steel is studied through a series of mechanical and thermal properties tests of materials such as quasi-static stretching at diferent temperatures.The mechanical properties test results show that the yield platform and hardening section of the tensile stress-strain curve gradually disappear with the increase of temperature in the range of 20⋅900∘C ，the curve tends to be flat， the tensile strength decreases by 90% at 900∘C ， and the elongation and section shrinkage after fracture increase significantlyindicating that the temperature increase leads to the plastic deformationof 45 steel.Young's modulus and Poisson's ratio of 45 steel are reduced to 60% and 28% of room temperature respectively at 700∘C ，and the stiffess of 45 steel is significantly reduced. The thermal performance test shows that the thermal conductivity basically stays at room temperature in the range of 20-800∘C ，and then decreases with the increase of temperature.The specific heat capacity increases gradually with the increase of temperature，and is more than twice of normal temperature at 700∘C .The linear expansion coefficient exhibits minor fluctuations

and reachesthehighestvalueat 700∘C

Key words ∴45 steel ;mechanical properties ; thermal properties ; tensile strength ; young's modulus ; thermal conductivity

以45钢构件为代表的钢材结构件由于材料抗拉强度、弹性模量等力学性能随温度的升高快速下降，在高温环境下表现出不可忽视的温度软化效应，极易引发断裂、开裂等失效[1-4]。（剩余5936字）