Study On The Fire Performance Of 12Cr1MoV And 15CrMo Steel

Pressure equipment using in the petrochemical industry and power industry often operates under the environment of high temperature and high pressure,involving flammable and explosive medium.The accidents such as overheat,fire,explosion,burning etc.cannot be avoided actually.Permanent deformation and damage of partial or global equipment could be caused by the fire and the local overheat,thereby influencing equipment's security and service life.A number of equipment has been damaged by the fire and the financial losses is heavy.The replacement or reparation of these devices may bring unbearable economic losses to the enterprise.Therefore,the damage change of the pressure equipment is needed to be mastered,in order to assess the applicability and safety rapidly and accurately.In this investigation,the damage of 12Cr1MoV steel and 15CrMo steel were studied through the thermal simulation test by measuring the mechanical properties and microstructure.The influencing factors include the heat exposure temperature(500,600,700,750,850 and 900 ?),heat exposure duration(1,2 and 5 hours)and cooling rate mode(air-cooled and water-cooled)etc.The microstructure observation contains the color change and the metallography.The tensile properties,impact energy and the fracture toughness are involved in the mechanical properties.It shows that the heat exposure duration has slight impact on the mechanical properties of both materials.In contrast,the heat exposure temperature and the cooling manner affect obviously.The influence of the heat exposure temperature on the material's properties can be ignored when the temperature is low.However,when the temperature increases to 850-900? and the water-cooled manner is applied,both the strength and hardness increase,and the plasticity and toughness decrease.