Hard alloy carburizing process resulting in gradient distribution of mechanical performance

A carburizing treatment and hard alloy technology, which is applied in the direction of metal material coating process, coating, solid-state diffusion coating, etc., can solve the problems of long carburizing treatment time, low carburizing reaction activity and low efficiency, and achieve Short carburizing treatment time, low production cost and energy consumption, and improved service life

Inactive Publication Date: 2004-09-08
ZIGONG CEMENTED CARBIDE CORP +1
View PDF0 Cites 34 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The solution of the present invention is to address the defects of the background technology that the carburizing agent has simple components, low carburizing reaction activity, long carburizing treatment time and low efficiency.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] This embodiment takes the carburizing treatment of yG6 spherical drill teeth as an example; the carburizing agent is made of Al with a purity of 99.0%. 2 o 3 : 40wt%, particle size is 1.2mm, C content is 99.5% graphite particle 20wt%, the purity is the sodium carbonate 40wt% of industrial pure grade and is formulated; the metallographic structure uniform yG6 that will be produced by conventional method together with infiltration The carbon agent is loaded into a boat with 2kg, the yG6 button is buried in the carburizing agent and then sent into the muffle furnace, carburized at a temperature of 1400°~1410°C for 80 minutes, and the surface WC+γ two-phase region (without η phase region) thick 2.4mm button, and the background technology is only 1.8mm thick without the η phase layer after carburizing for 3 hours.

[0017] In this embodiment, a φ45mm cemented carbide drill bit is used as a comparative test on a granite with a compressive strength of 270-320 MPa under the co...

Embodiment 2

[0019] This embodiment adopts the drill bit of φ 40mm made of cemented carbide WC-8% Co as an example:

[0020] The carburizing agent consists of 20wt% of calcium carbonate and potassium carbonate of industrial grade with a purity of 99.5% Al 2 o 3 : 40wt% and 20wt% of graphite particles with an average particle size of 1.5mm and a C content of 99.0%, prepared; the sintered carbide drill bit with a uniform metallographic structure is loaded into a boat as required and sent into a muffle furnace After carburizing at 1420°C for 110 minutes, a drill bit with a gradient structure of 2.5mm thick without η phase on the surface layer was obtained, and its average flexural strength reached 3490N / mm 2 . The drill bit is compared with the standard cemented carbide drill bit on the quartz sandstone. The result: the wear resistance is increased by 22.6%, and the average life is extended by 35.5%.

Embodiment 3

[0022] In this embodiment, a drawing die with a height of 16 mm, a diameter of 12 mm, and a diameter of sizing belt of 1.5 mm made from the mixed powder of WC-7% Co with a total carbon content of 5.25% is taken as an example:

[0023] Its carburizing agent consists of 45wt% calcium bicarbonate of industrial grade purity and 99.5% Al 2 o 3 : 40wt% and 15wt% of graphite particles containing 99.9% of C content and 1.2mm average particle size are formulated; 2.2kg of carburizing agent is mixed with the above-mentioned hard carbon steel with uniform texture and consistent mechanical properties inside and outside produced by conventional methods. The sintered body of the alloy wire drawing die is placed in a graphite boat together. After the carburizing agent is completely covered on the surface of the wire drawing die, it is sent into the muffle furnace for carburizing treatment at 1400°C for 60 minutes. After cooling, the surface gradient thickness reaches 1.8mm. There is no η ph...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
particle diameteraaaaaaaaaa
diameteraaaaaaaaaa
hardnessaaaaaaaaaa
Login to view more

Abstract

The hard alloy carburizing process resulting in gradient distributioin of mechanical performance includes the steps of preparing carburizing agent, loading into boat and carburizing treatment. The carburizing agent consists of Al2O3, graphite grain, and carbonate and/or bicarbonate in certain proportion and mixed together. During the carburizing treatment, carbonate and/or bicarbonate are decomposed into CO2, CO2 is then reacted with graphite to produce relatively active CO, and CO enters to liquid phase and reacts with eta phase to produce WC while immigrating inwards and to speed the formation of gradient structure inside the alloy. The present invention has the features of relatively low carburizing temperature, high comprehensive mechanical strength formed, short carburizing time, etc.

Description

technical field [0001] The invention belongs to a carburizing treatment method for hard alloy products, in particular to a carburizing treatment method that can make the mechanical properties of hard alloy products present a gradient distribution. This method is especially suitable for carburizing WC-Co hard alloy tools and molds to improve their comprehensive mechanical properties. Background technique [0002] Conventional WC-Co cemented carbide drill teeth, rock cutting and wire drawing dies have uniform internal and external metallographic structures and consistent mechanical properties. This kind of cemented carbide products with uniform structure has a contradiction between high hardness and wear resistance and toughness that is difficult to reconcile, that is, when the content of cobalt (Co) in the alloy is reduced to improve its hardness and wear resistance, the alloy body The toughness will decrease accordingly; otherwise, it will affect its hardness and wear resis...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C23C8/64
Inventor 刘咏羊建高王海兵张林秋龙郑易李克林
Owner ZIGONG CEMENTED CARBIDE CORP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap