Bearing steel surface treatment technology

Bearing steel in 450 ~ 650 ℃ temperature usually lose bearing capacity, large deformation, steel column, steel beam bending, the results due to excessive deformation can't continue to use, generally do not add to protect the fire resistance of bearing steel for 15 minutes. The length of this time is also related to the component heat absorption rate. To make the bearing steel material in the practical application to overcome the shortfalls, fire fire prevention must be carried out, its purpose is to increase the fire resistance of bearing steel is to limit the scope specified by the design specification. Prevent deformation in bearing steel in the fire rapidly warming cave, its measures is varied, the key is to adopt different methods according to different situations, such as thermal insulation, refractory materials cut off direct flame burning bearing steel, reduce the rate of heat transfer delay of bearing steel temperature, the intensity is weak, and so on. But no matter what method, the principle is the same. Here are several different bearing steel fire protection measures. A, outsourcing layer. Outsourcing is in bearing steel appearance add layer, can cast-in-situ forming, spraying method can also be adopted. Cast-in-situ molding outsourcing entities concrete layer usually use steel wire or steel to strengthen, to limit the shrinkage crack, and ensure the strength of the shell. Spraying method in the construction site of the bearing steel surface coated sand pump to form a protective layer, sand pump can be cement or lime plaster mortar, can be mixed with perlite or asbestos. While outsourcing layer can also use pearlite, asbestos cement, gypsum, or asbestos, light concrete precast slab, using adhesives, nail, bolt is fixed on the bearing steel. Second, the water filling ( Water jacket) 。 Filling water in the hollow type bearing steel is the most effective protective measures against fire. This method can make the bearing steel in the fire to keep low temperature, water cycle within the bearing steel, the quantity of heat of heat absorption material itself. The heated water can be recycled after cooling, or introduced by the pipe cold water to replace the heated water. Three, shielding. Bearing steel is set within the refractory material of the wall or ceiling, or component parcel in the space between the two pieces of wall, as long as can increase a few refractory or don't achieve the goal of fire. This is one of the most economic way to fire. Fourth, expand material. Fire retardant coating using bearing steel protection component, this method has good fireproof and heat insulation performance, without being limited by the bearing steel geometric construction etc, and generally do not need to add auxiliary facilities, and the coating quality is light, there are some beautiful adornment effect, belongs to the modern advanced fire prevention technology measures. At present, the top bearing steel construction increasing, especially some high-rise buildings, more widely adopt bearing steel material. High-rise buildings in case of fire, the fire is not in a short period of time can put out, this requests us in architectural design, and more fire protection in building material, in order to enhance its fireproof limit, and to formulate the necessary emergency plans within the building, in order to reduce casualties and property losses.