Preparation method of high-strength and high-toughness stainless steel powder for selective laser melting additive manufacturing

Abstract

The invention relates to a preparation method of high-strength and high-toughness stainless steel powder for selective laser melting additive manufacturing. The method comprises the following steps: S1, selecting composite components for burdening, carrying out vacuum induction heating melting, continuously refining till that a molten pool stops bubbling and furnace burden is completely cleared after molten steel is completely cleared, pouring the molten metal into a tundish heat preservation crucible, and flowing into a supersonic gas atomizing nozzle (self-made) through a flow guide pipe; S2, introducing high-pressure inert argon, forming a supersonic airflow, and atomizing the supersonic airflow into fine metal liquid drops; S3, enabling the liquid drops to become particles under surface tension in the air and to be rapidly cooled and solidified into a metal powder, and collecting the metal powder; and S4, screening according to requirements. According to the method, a reasonable component proportion is adopted, a gas atomizing nozzle is prepared from an environment-friendly polystyrene powder, the problem of black smoke is eliminated, complete dewaxing is achieved through a segmented dewaxing method, the service life is long, and the yield of powder meeting the requirement in the prepared metal powder is high; and the powder fluidity is good, and the performance of a test piece prepared through selective laser melting is obviously improved.

Description

technical field [0001] The invention belongs to the field of metal materials, and in particular relates to a preparation method of high-strength and high-toughness stainless steel powder for selective laser melting additive manufacturing. Background technique [0002] At present, metal material parts formed by metal additive manufacturing technology are gradually being used in aerospace, medical equipment, automobile manufacturing and other fields. Typical metal additive manufacturing technologies include laser selective melting, electron beam selective melting, and laser three-dimensional forming. , electron beam fuse deposition, etc. Selective laser melting (SLM) is a laser scanning a layer of metal powder pre-laid by the powder spreader in a chamber filled with inert gas according to a specific path, and the metal melts and forms a metallurgical bond with the previous layer. , so layer upon layer to form the desired entity; the metal powder used in this technology is fine...

AI Technical Summary

Problems solved by technology

[0005] (1) It is prepared by machining, but because the structure of the internal gas circuit is limited by the processing technology, it can only be split forged, and then assembled together by electric welding. The dimensional accuracy is poor, the material consumption is large, and the service life is short. The atomization effect is poor, and the yield of powder that meets the requirements is relatively low; (2) Investment casting process, the polystyrene core is prepared by using the 3D printing process SLS, and then the external temperature-resistant shell is prepared, and then the core material is removed by roasting , and finally cast the metal material, and shell it to get the finished product; currently, polystyrene material is dewaxed by high-pressure steam, which is easy to remain in the mold shell, and finally causes slag inclusion defects in the casting, and a large amount of black smoke is generated during roasting, causing heavy pollution

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