EXPERIMENTAL RESEARCH ON MECHANICAL PROPERTIES OF WATER-COOLED Q355 STEEL AFTER BEING SUBJECTED TO HIGH TEMPERATURE
-
摘要: 自2019年2月1日起,GB/T 1591—2018《低合金高强度结构钢》要求将原有的Q345钢更换为Q355钢,而火灾后钢材的残余力学性能是火灾后安全评价的关键指标。水冷却作为火灾中广泛应用的灭火方式,在大多数情况下是最为快速且高效的。因此,对高温浸水冷却后国产Q355钢材试件进行了单轴拉伸试验,获得高温水冷却后Q355钢材的应力-应变曲线和相关力学性能参数,并分析钢材高温后残余力学性能随温度的变化规律。此外,还对比分析了Q355钢材与Q235、Q460和Q690钢材高温后力学性能的差异。结果表明:受热温度低于600℃时,Q355钢材力学参数变化相对较小,屈服强度和弹性模量的变化幅度均未超过10%;温度超过600℃后,Q355钢材经浸水冷却后屈服强度和极限强度随温度升高而增大,弹性模量和伸长率却随温度的升高而降低;高温冷却后,Q355与Q235、Q460和Q690钢材的力学性能变化规律相似,但具体变化幅度却存在差异。最后,基于试验结果,建立了Q355钢材在水冷却方式下各力学参数随温度变化的数学模型,利用该模型可对火灾后Q355钢材的力学性能进行有效评估。Abstract: The Chinese National Standard High Strength Low Alloy Structural Steels(GB/T 1591-2018) requires that Q345 steel must be replaced by Q355 steel from February 1, 2019. Its residual mechanical properties after a fire are the key indicators for post-fire safety evaluation. As a widely-used fire extinguishing method in fire, water cooling is the fastest and most efficient firefighting method. Therefore, a uniaxial tensile test was conducted on the domestic Q355 steel specimens after water cooling from high temperature. The stress-strain curves and related mechanical properties of Q355 steel after water cooling from high temperature were obtained, and the variations of the residual mechanical properties of Q355 steel after water cooling high temperature were analyzed. The differences in mechanical properties of Q355 steel and Q235, Q460 and Q690 steels after cooling from high temperatures were also compared and analyzed. The results showed that when the heating temperature was lower than 600 ℃, the mechanical properties of Q355 steel had relatively small changes, and the maximum changes in yield strength and elastic modulus did not exceed 10%. When the temperature exceeded 600 ℃, the yield strength of Q355 steel after being immersed in water was cooled. And the ultimate strength increased with the increase of temperature, but the elongation decreased with the increase of temperature. After cooling from high temperatures, the Q355 steel had similar changes with Q235, Q460 and Q690 steels in mechanical properties, but the specific change range had differences. Finally, based on the test results, a mathematical model of the change in mechanical parameters of Q355 steel cooled by water was established. This model could be used to effectively evaluate the mechanical properties of Q355 steel after fire.
-
Key words:
- Q355 steel /
- high temperature /
- mechanical property /
- immersion cooling /
- mathematical model
-
[1] 潘韵,焦远帆,仵桂仓,等.我国钢结构的应用与发展前景[J].现代经济信息,2018(1):349. [2] LI G Q,LYU H B,ZHANG C.Post-Fire Mechanical Properties of High Strength Q690 Structural Steel[J].Journal of Construction Steel Research,2017,132:108-116. [3] 张有桔,朱跃,赵升,等.高温后不同冷却条件下钢材力学性能试验研究[J].结构工程师,2009,25(5):104-109. [4] 陈光鹏,张春涛.泡沫灭火后Q460高强钢力学性能试验研究[J].材料导报,2021,35(6):6151-6156. [5] 张春涛,金汉林,朱立.高温自然冷却后Q345钢材疲劳性能试验研究[J].建筑结构学报,2020,41(10):78-85. [6] 中国国家标准化管理委员会.金属材料拉伸试验第1部分:室温试验方法:GB/T 228.1-2010[S].北京:中国标准出版社,2010. [7] SAJID H U,KIRAN R.Influence of Stress Concentration and Cooling Methods on Post-Fire Mechanical Behavior of ASTM A36 Steels[J].Constr.Build.Mater,2018,186:920-945. [8] BALESHAN B,MAHENDRAN M.Numerical Study of High Strength LSF Floor Systems in Fire[J].Thin-Walled Structures,2016,101:85-99. [9] SAJID H U,KIRAN R.Post-Fire Mechanical Behavior of ASTM A572 Steels Subjected to High Stress Triaxialities[J].Engineering Structures,2019,191:323-342. [10] ZHOU H,WANG W,WANG K,et al.Mechanical Properties Deterioration of High Strength Steels After High Temperature Exposure[J].Construction and Building Materials,2019,199:664-675. [11] 陈建锋,曹平周.高温后结构钢力学性能试验[J].解放军理工大学学报(自然科学版),2010,11(3):328-333. [12] WANG W,LIU T,LIU J.Experimental Study on Post-Fire Mechanical Properties of High Strength Q460 Steel[J].Journal of Construction Steel Research,2015(114):100-109. [13] LI G Q,LYU H,ZHANG C.Post-Fire Mechanical Properties of High Strength Q690 Structural Steel[J].Journal of Construction Steel Research,2017(132):108-116. [14] KANG L,SUZUKI M,GE H,et al.Experiment of Ductile fracture Performances of HSSS Q690 After a Fire[J].Journal of Construction Steel Research,2018,146:109-121. [15] LU J,LIU H,CHEN Z,et al.Experimental Investigation into the Post-Fire Mechanical Properties of Hot-Rolled and Cold-Formed Steels[J].Journal of Construction Steel Research,2016,121:291-310. [16] 中国国家标准化管理委员会.低合金高强结构钢:GB/T 1591-2018[S].北京:中国标准出版社,2018.
点击查看大图
计量
- 文章访问数: 259
- HTML全文浏览量: 35
- PDF下载量: 11
- 被引次数: 0