Dewaxing and sintering integrated technique for large product of hard alloy

A technology for cemented carbide and large products, which is applied in the field of preparation of large cemented carbide products by the integrated process of dewaxing and sintering, which can solve the problems of insufficient control precision of the carbon content of the product, and achieve dewaxing efficiency, effective removal, and operation convenient effect

Active Publication Date: 2009-01-14
ZHUZHOU HARD ALLOY GRP CO LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] The purpose of the present invention is to overcome the technical defect of insufficient carbon content control accuracy in the sintering process of large cemented carbide products mixed with paraffin wax molding agent in the above two methods of removing the molding agent,

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  • Dewaxing and sintering integrated technique for large product of hard alloy
  • Dewaxing and sintering integrated technique for large product of hard alloy

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Embodiment 1

[0015] Embodiment 1 is to prepare φ 130mm cemented carbide top hammer, embodiment 2 is to prepare φ 160mm cemented carbide top hammer, and embodiment 3 is to prepare φ 216 (outer diameter), φ 160 (inner diameter), 72 (height) mm cemented carbide roll . The same process steps and process conditions adopted by the three embodiments are as follows, and the different process control parameters adopted by the three embodiments are shown in Table 1.

[0016] Since the dewaxing and sintering integrated process of the present invention adopts a hydrogen positive pressure atmosphere during the dewaxing process, in order to ensure safety, the furnace and the dewaxing pipeline are evacuated in advance, and leak detection is performed by a pressure rise method. After passing the leak detection, first fill the furnace with argon, and then replace the argon in the furnace with hydrogen. The hydrogen used is preferably hydrogen with a dew point ≥ -45°C, and the hydrogen pressure in the furna...

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Abstract

The invention discloses a cemented carbide dewaxing and sintering integrated process, which comprises the following steps: firstly, argon is filled in a furnace, then the argon is replaced by hydrogen, and the pressure in the furnace is controlled with 1.01X10<5> to 1.03X10<5> Pa; the multistep heat rising and preservation is performed on the condition that the hydrogen flow is 240 L/min to 260 L/min, and paraffin forming agent is eliminated; the atmosphere in the furnace is adjusted as a negative pressure during the heat preservation period after the temperature is increased to 450 DEG C, and the residual paraffin forming agent in the furnace is eliminated through adopting the hydrogen pulse pressure to scour; after the paraffin forming agent is eliminated, the temperature is increased to 1300 DEG C to 1350 DEG C to perform the vacuum sintering; the argon is filled in the late period of the vacuum sintering, and the argon protection sintering is performed at the temperature of 1350 DEG C to 1450 DEG C; after the argon protection sintering is completed, the argon is rapidly cooled. The process has the advantages that the multistep heat rising and preservation is performed on the condition of a micro-positive pressure hydrogen atmosphere, the dewaxing efficiency is high, the product has no peeling, the product carbon content control precision is very high, and the alloy cobalt magnetism value reaches 6.8 percent to 7.2 percent after the hold up hammer sintering.

Description

technical field [0001] The invention relates to a process method of dewaxing and sintering in hard alloy production, in particular to a method for preparing large hard alloy products through an integrated process of dewaxing and sintering. Background technique [0002] In the compression molding of the production of large cemented carbide products, paraffin wax molding agents must be mixed. However, the molding agent (ie dewaxing) must be removed before the sintering of the cemented carbide products. Usually, two modes are used to complete the removal of the molding agent. The first The first is the batch type, that is to use specific special equipment to complete the removal of the paraffin molding agent at a temperature of 600-800 ° C and a hydrogen protective atmosphere, and then the product is cooled and then transferred to a sintering furnace to complete sintering. The second is the continuous integrated type, that is, the molding agent removal and sintering process of ...

Claims

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Application Information

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IPC IPC(8): C22C1/04B22F3/10
Inventor 蒋洪亮王忆民王力民肖可俊周新华
Owner ZHUZHOU HARD ALLOY GRP CO LTD
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