Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Strong magnetic field vacuum annealing method for eliminating bulky Widmansttten structure in hypoeutectoid steel

A technology of Widmanstatten structure and hypoeutectoid steel, which is applied in the field of high magnetic field vacuum annealing to eliminate the coarse Widmanstatten structure in hypoeutectoid steel, can solve the problems such as the difficulty of eliminating Widmanstatten structure, and achieve the improvement of mechanical properties and plastic deformation effect of ability

Inactive Publication Date: 2009-06-03
NORTHEASTERN UNIV LIAONING
View PDF1 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, some literatures believe that once the coarse Widmanstatten structure is formed in hypoeutectoid steel, it is difficult to eliminate, and the higher the austenitizing temperature and the longer the holding time, the more difficult it is to eliminate the Widmanstatten structure

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
  • Strong magnetic field vacuum annealing method for eliminating bulky Widmansttten structure in hypoeutectoid steel
  • Strong magnetic field vacuum annealing method for eliminating bulky Widmansttten structure in hypoeutectoid steel
  • Strong magnetic field vacuum annealing method for eliminating bulky Widmansttten structure in hypoeutectoid steel

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] The material is high-purity Fe—0.52C alloy, the chemical composition is shown in Table 1, and its Ae is calculated by using Thermo—calc thermal analysis software. 3The temperature is 1037K. The heat treatment process is to heat the sample to 1067K, keep it warm for 5min, cool to 873K at 0.5K / min, and cool to room temperature with the furnace. During the heat treatment, 0T, 4T, 8T and 12T strong magnetic fields are applied respectively. The strong magnetic field generating device is a JMTD-12T100 superconducting direct current constant strong magnetic field generating device, which can generate a maximum magnetic field strength of 12T. The size of the sample is 7mm×7mm×1mm. After the heat-treated sample is ground, polished and corroded with 3% nital solution, the microstructure is observed with an Olympus optical microscope. The metallographic observation surface is a section parallel to the direction of magnetic field application, and the direction indicated by the arr...

Embodiment 2

[0030] The material is high-purity Fe-0.52C alloy, chemical composition and Ae 3 Temperature is identical with embodiment 1. The heat treatment process is to heat the sample to 1067K, hold it for 5min, cool it to 873K at different cooling rates (0.5K / min, 2K / min, 5K / min), and cool it to room temperature with the furnace. magnetic field. The strong magnetic field generating device, the sample size and the sample processing and microstructure observation after heat treatment are all the same as in Example 1.

[0031] Figure 4 It is the microstructure of high-purity Fe-0.52C alloy after heat treatment with different cooling rates (0.5K / min, 2K / min, 5K / min) under non-magnetic field and 12T magnetic field. Depend on Figure 4 It can be seen that the non-magnetic field heat-treated samples ( Figure 4 (a), (b), (c)) in the microstructure, the pro-eutectoid ferrite is needle-like Widmanstatten ferrite and a small amount of equiaxed ferrite. Among them, the distribution of ferr...

Embodiment 3

[0033] The material is high-purity Fe-0.36C alloy, and its chemical composition is shown in Table 2. Ae 3 The temperature is 1069K. The heat treatment process is to heat the sample to 1099K, keep it warm for 5min, cool to 873K at a cooling rate of 0.5K / min, and cool to room temperature with the furnace. During the heat treatment process, 0T and 12T strong magnetic fields are applied respectively. The strong magnetic field generating device, the sample size and the sample processing and microstructure observation after heat treatment are the same as in Example 1.

[0034] Table 2. Chemical composition of Fe—0.36C alloy (mass%).

[0035]

[0036] Figure 5 shown as Figure 5 . The microstructure of Fe—0.36C alloy under the condition of 0T or 12T magnetic field, after 1099K, 5min austenitization, cooling to 873K at a cooling rate of 0.5K / min, and then furnace cooling to room temperature. Similar to the Fe-0.52C alloy, the magnetic field is 0T after heat treatment ( Figu...

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 strong magnetic field vacuum annealing process for eliminating massive widmannstatten structure in hyposteel includes the following steps: loading workpiece into a vacuum heat treating furnace, raising the vacuum degree in the furnace to (6-8)x10<->3 Pa, raising the magnetic field strength to over 10T, raising the temperature in highest temperature heating rate to Ae3+30K and maintaining for 1-1.5 min / mm for austenizing, cooling the workpiece in the cooling rate lower than 30 K / min to 873K, cooling the workpiece inside the furnace to room temperature, and removing magnetic field and vacuum. The process can eliminate massive widmannstatten structure from hyposteel, obtain homogeneous fine diffusive microstructure, raise the mechanical performance and plastic deformation capacity of hyposteel.

Description

technical field [0001] The invention belongs to the technical field of heat treatment of metal materials, and in particular relates to a strong magnetic field vacuum annealing method for eliminating coarse Widmanstatten structures in hypoeutectoid steel. In this method, during the vacuum annealing process of the hypoeutectoid steel, the superconducting direct current steady strong magnetic field is applied to eliminate the coarse proeutectoid Widmanstatten ferrite in the hypoeutectoid steel that has a destructive effect on the mechanical properties, and obtain a uniform structure. , Improve the mechanical properties of hypoeutectoid steel. Background technique [0002] After casting, forging, rolling, welding and heat treatment of hypoeutectoid steel with carbon content less than 0.6% (mass %), needle-like proeutectoid Widmanstatten ferrite can often be observed in the microstructure. The effect of proeutectoid Widmanstatten ferrite in hypoeutectoid steels on mechanical pro...

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 Patents(China)
IPC IPC(8): C21D9/00C21D1/78C21D1/26C21D10/00
Inventor 王守晶赵骧何长树左良
Owner NORTHEASTERN UNIV LIAONING
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com