Fire patterns may be generated on the soleplate of any electric iron when it is subject to overheating failure.In this paper,experiments were conducted to simulate the overheating failure of electric irons.DTA,TG,SEM,EDS,hardness measurement,metallurgic test and temperature measurement were used to analyze the material properties and fire pattern variations during overheating failure.It was concluded that the fire patterns on electric iron soleplate formed during overheating failure differ greatly from those due to fire,especially in macro morphology,hardness distribution and microscopic structure.The results provide new technical basis data for fire investigation,and can be applied to the fire scene survey,material evidence collection and identification.