Method for adopting powder metallurgy hot isostatic pressing near-net-shape forming technology for preparing motor protecting ring

A powder metallurgy heat and motor guard ring technology, applied in the field of metal materials, can solve the problems of complex process, easy cracks on the surface of the guard ring, uneven internal structure and performance, etc., and achieves simple process, fine grain, and uniform structure and performance. Effect

Active Publication Date: 2014-09-17
HEBEI WUWEI AERO & POWER TECH +1
View PDF5 Cites 3 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to solve the technical problems existing in the multi-fire forging process that the

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

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for adopting powder metallurgy hot isostatic pressing near-net-shape forming technology for preparing motor protecting ring

Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0008] (1) The preparation size is Φ600mm (outer diameter) × 50mm (wall thickness) × 400mm (height) P900 (18Cr-18Mn-0.6N) retaining ring (Note: the size is the size before cold expansion)

[0009] First, the alloy is smelted according to the requirements of P900 (18Cr-18Mn-0.6N) alloy composition, and the powder is made by the nitrogen atomization process, and the average particle size of the powder is controlled at 10μm; then the low carbon steel welding sheath is used, and the final product size is required. Considering the influence of sintering shrinkage, the size of the sheath is Φ720mm (outer diameter) × 60mm (wall thickness) × 480mm (height); the powder is packed into the sheath and compacted, and vacuumed to 10 -1 After Pa, perform welding and sealing, and perform hot isostatic pressing sintering densification after welding. The sintering temperature is 1220℃, pressure is 100MPa, and the holding time is 60min. The sintering and densification treatment is performed to obtain...

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

No PUM Login to view more

Abstract

The invention provides a method for adopting a powder metallurgy hot isostatic pressing near-net-shape forming technology for preparing a motor protecting ring and belongs to the field of metal materials. The protecting ring is made of a protecting ring steel material with the nitrogen content of 0.4-1.0%, the process of combining a pressurizing induction melting of mother alloy and nitrogen atomization is adopted for preparing powder with the average granularity of 5 micrometers-100 micrometers, the powder is placed into a cylindrical or a circular-ring-shaped bag sleeve, then vacuumizing and seal welding are carried out, then the powder is placed in a hot isostatic pressing furnace for pressurization and heat preservation, compacting is carried out on the powder to obtain a protecting ring blank, the bag sleeve is turned off through a machining method, cold swelling formation and annealing stress relief are carried out on the blank, the processing temperature ranges from 330 DEG C to 350 DEG C, the speed of temperature rising is smaller than 40 DEG C per hour, the speed of temperature falling is smaller than 30 DEG C per hour, and time for heat preservation ranges from 10 minutes-12 minutes. According to the method, the texture performance is uniform, the crystal particles are small, the overall performance of products is high, the use reliability of the protecting ring and a whole machine can be improved greatly, surface cracks of the protecting ring in the manufacturing process can be effectively avoided, the protecting ring is treated in the mode of being free from solid solutions, the rate of finished products is effectively increased, and the manufacturing cost can be effectively lowered.

Description

technical field [0001] The invention belongs to the field of metal materials, and relates to a method for preparing a motor retaining ring by using powder metallurgy hot isostatic pressing near-net forming technology. Background technique [0002] The retaining ring is a large forging steel ring that is pressed and assembled at both ends of the generator rotor, and is one of the large key parts of thermal power generation equipment. The force of the retaining ring is complicated during high-speed rotation. It not only has to bear huge centrifugal force, but also bears the assembly stress during shrink fitting, the additional stress caused by uneven load, the alternating stress from the rotor and the structural requirements. concentrated stress. Therefore, in order to ensure the long-term safe operation of the unit, the retaining ring is required to have sufficient strength, good toughness, uniform mechanical properties and minimum residual stress. The retaining ring works ...

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
IPC IPC(8): B22F3/14B22F5/10
Inventor 祁进坤方玉城王雪欣任淑彬赵钢寇晓磊
Owner HEBEI WUWEI AERO & POWER TECH
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