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KR-102963993-B1 - Powder Metallurgical Manufacturing Method of Insert Collet for Seismic Concrete Structures

KR102963993B1KR 102963993 B1KR102963993 B1KR 102963993B1KR-102963993-B1

Abstract

The present invention comprises: (a) a raw material preparation step of preparing an alloy powder composed of Fe-3Cr-1V, copper (Cu) powder, carbon (C) powder, and a lubricant; (b) a mixing step of introducing and mixing 2.5wt% to 3.5wt% of copper (Cu) powder, 0.4wt% to 0.6wt% of carbon (C) powder, and 0.6wt% to 0.8wt% of lubricant into a mixing chamber per 100wt% of the alloy powder composed of Fe-3Cr-1V; (c) a molding step of pressurizing the mixture containing the alloy powder, copper (Cu) powder, carbon (C) powder, and lubricant to manufacture an insert collet molded body; and (d) a sintering and curing step of sintering and curing the insert collet molded body. The present invention provides a method for manufacturing a powder metallurgy insert collet for seismic-resistant concrete structures, comprising: (e) a steam treatment step of steam-treating the insert collet after sintering and hardening is complete to improve the corrosion resistance, impact toughness, and tensile strength of the insert collet.

Inventors

  • 문종학

Assignees

  • (주)아이엔아이 분말야금

Dates

Publication Date
20260511
Application Date
20250714

Claims (9)

  1. (a) A raw material preparation step for preparing an alloy powder composed of Fe-3Cr-1V, copper (Cu) powder, carbon (C) powder, and a lubricant; (b) A mixing step of introducing 2.5 wt% to 3.5 wt% of copper (Cu) powder, 0.4 wt% to 0.6 wt% of carbon (C) powder, and 0.6 wt% to 0.8 wt% of lubricant into a mixing chamber and mixing them, per 100 wt% of alloy powder composed of Fe-3Cr-1V; (c) A molding step of manufacturing an insert collet molded body by press-pressing a mixture comprising the finished alloy powder, copper (Cu) powder, carbon (C) powder, and lubricant; (d) a sintering and hardening step for sintering and hardening the insert collet molded body; and (e) a steam treatment step for improving the corrosion resistance, impact toughness, and tensile strength of the insert collet by steam treating the insert collet after sintering and hardening are complete; and The above step (b) is, (b1) A first mixing step in which the alloy powder is stirred alone for a certain period of time to align the particle size shape of the alloy powder and homogenize the alloy powder; (b2) A second mixing step in which copper (Cu) powder is sprinkled onto the surface of the alloy powder and then stirred for a certain period of time to coat the surface of the alloy powder with the copper (Cu) powder; (b3) a third mixing step of mixing carbon (C) powder in a certain weight ratio into the mixture of the alloy powder and copper (Cu) powder; and (b4) A fourth mixing step in which a lubricant is applied to a mixture of the alloy powder, copper (Cu) powder, and carbon (C) powder, and then mixed for a certain period of time to coat the surface of each powder with the lubricant; A method for manufacturing a powder metallurgy insert collet for seismic-resistant concrete structures, characterized by including
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  3. In paragraph 1, A method for manufacturing powder metallurgy insert collets for seismic-resistant concrete structures, characterized in that the above lubricant includes EBS Wax (Ethylene-bis-stearamide).
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  5. In paragraph 1, The above step (b) is, The above alloy powder is stirred at 25 to 30 rpm for 10 minutes, and The alloy powder and copper (Cu) powder, the mixture of the alloy powder and copper (Cu) powder, and carbon (C) powder are each stirred at 25 to 30 rpm for 5 to 8 minutes. A method for manufacturing a powder metallurgy insert collet for seismic-resistant concrete structures, characterized by mixing the above lubricant with a mixture of alloy powder, copper (Cu) powder, and carbon (C) powder at 15 rpm for 5 minutes, and then mixing further at 8 rpm to 10 rpm for 2 minutes.
  6. In paragraph 1, The above step (c) is, A method for manufacturing a powder metallurgy insert collet for seismic-resistant concrete structures, characterized by applying the above mixture to a uniaxial press at a pressure of 6 to 8 Ton/ cm² to form an insert collet molded body, and imparting a density of 6.6 to 7.2 g/ cm³ to the insert collet molded body.
  7. In paragraph 1, The above step (d) is, (d1) a step of forming an internal atmosphere of a continuous sintering furnace that maintains reducing power by mixing 5 vol% of hydrogen ( H₂ ) with a nitrogen ( N₂ ) base, and sintering at a sintering temperature of 1,120℃ to 1,150℃ for 20 to 30 minutes; and (d2) A rapid cooling step in which the sintered insert collet molded body is rapidly cooled using nitrogen ( N₂ ) gas to directly transform the structure of the insert collet molded body into martensite; A method for manufacturing a powder metallurgy insert collet for seismic-resistant concrete structures, characterized by including
  8. In Paragraph 7, The above step (d) is, (d3) After step (d2) above, A step of uniformly distributing heat of 200°C to the surface of an insert collet molded body for 4 minutes to relieve residual stress in the insert collet molded body and stabilize a small amount of remaining austenite; A method for manufacturing a powder metallurgy insert collet for seismic-resistant concrete structures, characterized by further performing the following.
  9. In paragraph 1, The above step (e) is, (e1) A step of forming an oxide film ( Fe₃O₄ ) on the surface of an insert collet molded body by introducing the insert collet into a steam treatment chamber and then performing a thermochemical treatment in saturated steam at 570°C to 600° C for 30 to 90 minutes; (e2) a step of partially transforming (tempering) the insert collet on which the oxide film has been formed; and (e3) After step (e2) above, a step of shutting off the steam supplied to the steam treatment chamber and cooling to 10℃/min or lower while discharging moisture by injecting 20L/min of nitrogen; A method for manufacturing a powder metallurgy insert collet for seismic-resistant concrete structures, characterized by including

Description

Powder Metallurgical Insert Collet Composition for Seismic Concrete Structures and Method of Manufacturing the Same The present invention relates to a powder metallurgy insert collet composition for seismic-resistant concrete structures and a method for manufacturing the same. More specifically, the invention relates to a powder metallurgy insert collet composition for seismic-resistant concrete structures and a method for manufacturing the same, wherein the insert collet is formed using an alloy composition having high strength and high corrosion resistance, and surface hardness and corrosion resistance can be improved through sintering hardening and steam treatment processes. Generally, an insert collet is an accessory of an anchor device embedded with a sleeve during the formwork stage to securely pre-fix equipment loads in concrete structures. It is typically divided into 3 to 6 sleeve pieces that spread evenly in a radial direction, and is configured so that a tapered cone and an anchor rod fitted behind the collet can directly transmit pull-out and shear loads to the structure. This eliminates the need to drill a separate hole in the structure at the construction site, thereby reducing dust and noise and significantly shortening construction time. These conventional insert collets utilized materials formed by casting or machining and reinforced through heat treatment, but they had problems such as difficulty in securing seismic performance, insufficient durability against repetitive loads, and susceptibility to failure when exposed to corrosive environments for extended periods. The background technology or prior art mentioned herein is intended only to aid in understanding the technical significance of the present invention and does not refer to technology widely known in the technical field to which this invention belongs prior to the filing of the present invention. FIGS. 1 and 2 are flowcharts illustrating the process of manufacturing a powder metallurgy insert collet for a seismic-resistant concrete structure according to one embodiment of the present invention. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, it should be noted that in assigning reference numerals to the components of each drawing, the same components are given the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, it should be noted that technical terms used in describing the present invention are used merely to describe specific embodiments and are not intended to limit the invention. Detailed descriptions of related known components or functions are omitted if it is determined that such descriptions could obscure the essence of the invention. Additionally, general terms used in describing the present invention should be interpreted according to their prior definitions or the context, and should not be interpreted in an overly narrow sense. If a technical term is incorrect and fails to accurately express the concept of the invention, it should be replaced with a technical term that can be correctly understood by a person skilled in the art. Furthermore, in describing the present invention, terms such as "comprising," "composing," or "having" mean that the relevant components may be inherent unless specifically stated otherwise, and should not be interpreted as necessarily including all of the various components or steps, and should be interpreted as meaning that some of the components or steps may not be included, or that additional components or steps may be included; and all terms, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains, unless otherwise defined. In addition, identification symbols such as 1, 2, A, B, (a), (b), etc. may be used to describe the components of the present invention. These identification symbols are intended to distinguish the components from other components and are used only for convenience of explanation; they do not limit the essence, order, or sequence of the components. Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. As described above, the method for manufacturing a powder metallurgy insert collet for a seismic-resistant concrete structure according to the present invention first performs a raw material preparation step (S110) of preparing the components constituting the insert collet in powder form and preparing a lubricant to be added when mixing these components. The raw material preparation step (S110) is a step of preparing an alloy powder that forms the main component among the components forming the insert collet, a mixed powder to be mixed with the alloy powder, and a lubricant. Here, the alloy powder may be an alloy powder in which iron (Fe), chromium (Cr) and vanadium (V) a