Mechanical properties and microstructure evolution of 304 stainless steel under electric fire
The mechanical properties and microstructure of 304 stainless steel under different heat input conditions in power fire scenes were studied,and the relationship between mechanical properties and microstructure evolution of 304 stainless steel under maximum fire temperature and different cooling conditions was analyzed.The results show that the holding time has little effect on the mechanical properties of 304 stainless steel at the same temperature.The tensile strength and yield strength of 304 stainless steel decreased linearly with the increase of temperature,respec-tively to 34.5 MPa and 13 MPa at 1 100 ℃,and the elongation after fracture increased linearly,increasing to 132％at 1 100 ℃.At 1 100 ℃,when the holding time is less than 30 min,multiple grains merge into a large grain and grow gradually.When the holding time is greater than 30 min,annealing twins begin to appear inside the large grains,and the grain and structure no longer change.The cooling conditions have little effect on the overall mechan-ical properties of 304 stainless steel.The change rate of tensile strength under different fire conditions is not more than 5％compared with room temperature,and the change rate of yield strength under room temperature～1 000 ℃ is not more than 10％.At 1 100 ℃,the yield strength under air cooling and water cooling conditions drops to 81％and 86％respectively.This is mainly due to the obvious grain growth at 1 100 ℃,and the average grain size reaches 86.1 pm.
electric fire304 stainless steelmicrostructuretensile strengthyield strengthfracture elongation
NETL
NSTL
万方数据
维普
