Hard alloy and process for local laser coating of hard alloy

A cemented carbide and laser coating technology, applied in metal material coating technology, metal processing equipment, coating and other directions, can solve the problem of weak bonding between the alloy layer and the base metal, and achieve the elimination of inclusion elements and good flow performance. , the effect of high hardness

Active Publication Date: 2018-03-06
佛山铸昊机械设备有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] Aiming at the problem that the coated alloy layer is not firmly combined with the base metal in the prior art, the present invention provides a cemented carbide and local laser coating cemented carbide process

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] A cemented carbide, the composition of which is as follows in terms of weight percentage: Cr: 20; W: 10; C: 1.5; Ni: 21; Fe: 1; Si: 0.8; B: 1; Re: 1.5; the balance is Co , the cemented carbide is in powder form and the particle size of the powder is 40-200um. In this embodiment, the particle size of the cemented carbide powder is 200um.

[0030] When the laser cladding cemented carbide process is applied, on the one hand, due to the high energy density of the laser, the temperature of the molten pool during the cladding process is high. After the laser beam is removed, the molten pool condenses rapidly, and alloy elements such as Si and B cannot effectively float up. Part of the brittle elements remain in the cladding layer, resulting in increased crack sensitivity of the cladding layer, and the surface hardness of the alloy layer is not high; on the other hand, the large difference in expansion coefficient between the alloy layer and the substrate leads to The bond is ...

Embodiment 2

[0035] A kind of cemented carbide, each composition is as follows according to weight percentage: Cr: 19; W: 8; C: 0.7; Ni: 13; Fe: 1; B: 1.7; Re: 1.5; The cemented carbide is in powder form and the particle size of the powder is 40-200um. In this embodiment, the particle size of the cemented carbide powder is 40um.

[0036] This embodiment strictly controls the addition of B elements and Si elements. The purpose is to ensure that the cemented carbide has certain self-fluxing, deoxidation, and slag-forming capabilities, and can "wet" the surface of the substrate, and avoid boron in the cladding process. It cannot float up, which increases the crack sensitivity of the cladding layer; at the same time, it reduces the melting point and expands the temperature range of the solid and liquid phases of the alloy, so that the alloy has good fluidity and good wettability to the surface of the substrate during the melting process And showed excellent metallurgical bonding.

[0037] The...

Embodiment 3

[0039] The hob cutter body and the upper and lower covers are usually made of national standard 42CrMo. After forging, normalizing and rough machining, the material is quenched and tempered according to the heat treatment process. The general technical requirements for the upper and lower covers are HB250-280, and the technical requirements for the cutter body are HRC40- 45. This technical requirement is to take into account the processing performance, mechanical properties and use strength of the material. The complex and changeable formation conditions have very high requirements on the cutting tool, and the outside of the hob is severely worn during operation. Therefore, further improving the mechanical properties of the outside of the hob can increase the service life.

[0040] In order to ensure the reasonable maintenance of the tool, the materials of the above-mentioned tool appearance parts are partially laser-coated with cemented carbide after the normal quenching and t...

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Abstract

The invention discloses a hard alloy and a process for local laser coating of the hard alloy, belonging to the technical field of surface-hardening treatment of metal. The hard alloy comprises, by weight, 20 to 27% of Cr, 10 to 14% of W, 1.5 to 2.5% of C, 21 to 23% of Ni, 1% of Fe, 0.8 to 1% of Si, 1% of B and 1.5% of Re, with the balance being Co. The hard alloy is powdery and has a powder size of 40 to 200 [mu]m. The powdery alloy material used in the invention has good compatibility with a matrix material, the dilution rate of a cladding layer is small, and the thermal expansion coefficients of the two materials are almost same; through pretreatment and post-heat-treatment of a matrix and the cladding layer, temperature gradient is further reduced and internal thermal stress in the cladding layer is decreased, and thus, the phenomena of cracks and shedding of an alloy layer are avoided; therefore, the hard alloy overcomes the problem of infirm bonding between a coated alloy layer and matrix metal in the prior art and has the characteristics of high hardness and good wear resistance.

Description

technical field [0001] The invention belongs to the technical field of metal surface hardening treatment, and more specifically relates to a hard alloy and a local laser coating hard alloy process. Background technique [0002] In the field of underground engineering, the application of shield construction method is more and more extensive. The shield construction method is widely used in tunneling in hard rock sections. The shield machine in underground engineering is bulky and heavy, and the underground working space is limited. When working, the cutter head of the shield machine rotates to drive various knives on it to complete the excavation of the soil. The hob body and upper and lower covers of the shield machine are parts that are in direct contact with cuttings and rocks. They are prone to wear and tear during operation and need to be replaced in time. The quality of hob cutter body and upper and lower covers directly affects the rock-breaking ability, tunneling ef...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C30/00C22C19/07B22F1/00C23C24/10
CPCC22C19/07C22C30/00C23C24/103B22F1/052
Inventor 邰淼韩文进
Owner 佛山铸昊机械设备有限公司
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