Method for preparing porous foam steel by melt foaming process and apparatus thereof

Abstract

The invention provides a method and a device for preparing porous blister steels through foaming of fused masses. The method comprises the following steps: firstly, a foaming agent is flatly laid at the bottom of a crucible and covered with a stainless steel mesh, so as to prevent the foaming agent from floating upward; secondly, the crucible is placed into a heating furnace for heating until the temperature is 50 to 100 DEG C lower than the temperature that the foaming agent begins to discompose, and molten steels are poured into the crucible; thirdly, a heat-insulated heating device is utilized to adjust the temperature of the molten steels in the crucible until the temperature is 250 to 350 DEG C above the temperature that the foaming agent begins to discompose; and fourthly, after heat preserved stirring for 1 to 2 minutes, the crucible is taken out and air-cooled to the room temperature, and the porous blister steel materials are obtained. The method and the device can increase the residence time of the molten steels within a temperature region for decomposing the foaming agent, prevent the foaming agent from floating upward, and improve the structural characteristics and the distribution characteristics of holes of prepared samples, has simple technique, is easy to operate, and is an ideal method for preparing the porous blister steels.

Description

technical field [0001] The invention relates to a process for preparing porous foamed steel, in particular to a method for preparing porous foamed steel by a melt foaming method and a device for realizing the method, belonging to the technical field of porous material preparation. Background technique [0002] Metal foam is a new type of material developed in the 1940s. At present, the research on metal foam mainly focuses on the research on metals with low melting point, and the research on porous steel foam with high melting point is still in its infancy. [0003] The development of modern industry has higher and higher requirements on the structure and performance of materials. For some special materials, not only light weight is required, but also high strength requirements are required, such as materials used in the aerospace field and so on. Compared with foamed aluminum and other low-melting point metal foams, which are the most widely studied at present, foamed steel...

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Problems solved by technology

[0004] At present, the method of preparing foamed steel mainly adopts powder metallurgy sintering method. For the preparation of porous foamed steel by melt foaming, there are mainly the following difficulties: (1) The temperature of molten steel is high, and the cooling speed is fast during casting and foaming. The fixed residence time in the foaming temperature range is short; (2) When the molten steel is cast, the buoyancy is relatively large, the density of the foaming agent is lower than that of the molten steel, and a large amount of foaming agent floats to the surface of the molten steel, resulting in poor foaming effect; (3) The foaming agent is in direct contact with the molten steel during casting, and when the foaming agent heats up rapidly and reaches the decomposition temperature, it decomposes rapidly, resulting in low viscosity of the molten steel and a large amount of gas escaping; (4) The generated bubbles are unstable, due to The viscosity of molten steel is low, and the generated air bubbles receive little resistance during the rising process, resulting in large air bubbles and uneven distribution of air bubbles in the product

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