Heat treatment process for improving spheroidized structure of large-sized die flat steel forged material

A large-scale, ultra-fine treatment technology, applied to 1.2344 mold flat steel, heat treatment process for improving the spheroidized structure of large-scale mold flat steel forgings, and heat treatment technology for improving the spheroidized structure of large-scale mold flat steel 1.2344 forgings , can solve the problems of poor spheroidized structure level, coarse steel structure, harsh use environment, etc., and achieve the effect of improving structure uniformity, increasing carbide level, and improving microstructure

Active Publication Date: 2017-08-18
FUSHUN SPECIAL STEEL SHARES
View PDF2 Cites 7 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The spheroidized microstructure of 1.2344 mold flat steel produced by Fushun Special Steel Co., Ltd. is between AS8-AS9 according to the rating of NADCA#207 of the North American Die Casting Association, such as figure 2 , image 3 ;With the development of the mold industry, the demand for large-size molds is increasing day by day, and the environment in which the molds are used is becoming more and more harsh, and the service life of the molds has attracted more and more attention from users. Equally seriously affect the service life of the mold
At present, the ways to improve the spheroidizing structure of 1.2344 series hot work die steel are normalizing after forging + isothermal spheroidizing annealing, but due to the low cooling intensity of normalizing, the effect is not bad for small-sized bars or modules, but for large-sized forged As for the forged material, due to the large size and the current cooling method, the core is prone to precipitate network carbides, and the spheroidized structure level is poor, resulting in uneven structure of the forged material, which affects later use.

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
  • Heat treatment process for improving spheroidized structure of large-sized die flat steel forged material
  • Heat treatment process for improving spheroidized structure of large-sized die flat steel forged material
  • Heat treatment process for improving spheroidized structure of large-sized die flat steel forged material

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Specifications: 365mm×900mm,

[0032] Such as figure 1 As shown, the processing technology is as follows:

[0033] Step 1: After forging, send the red to the annealing furnace for material: the temperature of the annealing furnace is 512 ° C ~ 560 ° C;

[0034] Step 2: Superfine treatment: preheating temperature is 750°C during normalizing heating, heating rate is 69°C / h, holding time is 1.5min / mm, normalizing temperature is 980°C, holding time is 1.5min / mm; water is used for normalizing cooling Alternating space technology improves the cooling strength, refines the coarse grains produced by high-temperature forging, eliminates the network carbide structure, and controls the material temperature at 320°C to 351°C;

[0035] Step 3: After normalizing, adopt the isothermal spheroidizing annealing process. The isothermal spheroidizing annealing holding temperature is 890°C, the heating rate is 70°C / h, and the holding time is 1.5min / mm, and then the temperature is reduced...

Embodiment 2

[0037] Specifications: 420mm×900mm,

[0038] Such as figure 1 As shown, the processing technology is as follows:

[0039] Step 1: After forging, send the red to the annealing furnace for material: the temperature of the annealing furnace for material is 520 ° C ~ 561 ° C;

[0040] Step 2: Superfine treatment: Preheating temperature is 750°C during normalizing heating, heating rate is 70°C / h, holding time is 1.5min / mm, normalizing temperature is 980°C, holding time is 1.5min / mm; water is used for normalizing cooling Alternating space technology improves the cooling strength, refines the coarse grains produced by high-temperature forging, eliminates the network carbide structure, and controls the material temperature at 320°C to 350°C;

[0041] Step 3: After normalizing, use isothermal spheroidizing annealing treatment process. The isothermal spheroidizing annealing temperature is 890°C, the heating rate is 68°C / h, the holding time is 1.5min / mm, and then the temperature is re...

Embodiment 3

[0043] Specifications: 360mm×910mm,

[0044] Such as figure 1 As shown, the processing technology is as follows:

[0045] Step 1: After forging, send the red to the annealing furnace for material: the temperature of the annealing furnace for material is 515 ° C ~ 555 ° C;

[0046] Step 2: Superfine treatment: preheating temperature is 750°C during normalizing heating, heating rate is 75°C / h, holding time is 1.5min / mm, normalizing temperature is 980°C, holding time is 1.5min / mm; water is used for normalizing cooling Alternating space technology improves the cooling strength, refines the coarse grains produced by high-temperature forging, eliminates the network carbide structure, and controls the material temperature at 310°C to 342°C;

[0047]Step 3: After normalizing, adopt the isothermal spheroidizing annealing process. The isothermal spheroidizing annealing temperature is 890°C, the heating rate is 70°C / h, the holding time is 1.5min / mm, and then the temperature is reduced...

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 discloses a heat treatment process for improving the spheroidized structure of a large-sized die flat steel forged material. The purpose is to improve the spheroidized microstructure of the forged material. The process combination of post-forging red sending annealing material waiting+superfine treatment+isothermal spheroidizing annealing treatment is designed. Precipitation of secondary net carbide can be reduced through post-forging red sending annealing material waiting, and preparation is made for subsequent superfine treatment and isothermal spheroidizing annealing. During superfine treatment, normalizing heating adopts one time of preheating, complete burning of steel is ensured, inner and outer temperatures are uniform, normalizing cooling adopts water and air alternate cooling, cooling intensity is improved, thus coarse grains produced by high-temperature forging are refined, the net carbide structure is eliminated, and then small and uniform globular pearlites and a few of dispersively distributed granular carbide are obtained through isothermal spheroidizing annealing. The heat treatment process has the following beneficial effects that with the adoption of the treatment process, the coarse structure of the steel is eliminated, structure uniformity is improved, the carbide level is improved, and the microstructure reaches the AS1-AS4 level.

Description

technical field [0001] The invention relates to the field of post-forging heat treatment of large-size die flat steel, in particular to a heat treatment process for improving the spheroidized structure of large-size die flat steel forgings, and in particular to 1.2344 die flat steel. technical field [0002] The invention relates to the field of post-forging heat treatment of large-scale mold flat steel, in particular to a heat treatment process for improving the spheroidized structure of large-scale mold flat steel 1.2344 forging. Background technique [0003] 1. 2344 hot work die steel has good thermal strength, red hardness, high toughness, thermal fatigue resistance and thermal crack resistance, and is mainly used in forging dies, hot extrusion dies, die-casting dies and other fields. The spheroidized microstructure of 1.2344 mold flat steel produced by Fushun Special Steel Co., Ltd. is between AS8-AS9 according to the rating of NADCA#207 of the North American Die Ca...

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): C21D9/52C21D1/32C21D1/28
CPCC21D1/28C21D1/32C21D9/52
Inventor 牛伟崔鸿孙大利李涛秋立鹏刘宝石韩凤军包文全刘桂江
Owner FUSHUN SPECIAL STEEL SHARES
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