Organization control method of large-size pre-hardening type plastic die steel module

A technology of plastic mold steel and control method, applied in the direction of heat treatment process control, manufacturing tools, heat treatment equipment, etc., can solve the problems of difficult hardening, roughness, affecting mold processing and service performance, etc., to achieve good process stability and reduce microcracks Effect

Active Publication Date: 2010-06-16
SHANGHAI UNIV
View PDF1 Cites 6 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Liu Zongchang and others pointed out in the article "Structure and Pre-hardening Treatment of 718 Plastic Mold Steel" ("Special Steel", April 2002, Vol.23.No.2: 43-45) that the effective thickness of 718 steel is 100-500mm After forging, the block oil quenching is difficult to harden, and martensite + bainite structure is obtained, or completely bainite structure. The tempered troostite structure obtained by quenching martensite after tempering is uniform and fine, while quenching The tempered structure of bainite is relatively coarse, which affects the processing and performance of the mold

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
  • Organization control method of large-size pre-hardening type plastic die steel module
  • Organization control method of large-size pre-hardening type plastic die steel module
  • Organization control method of large-size pre-hardening type plastic die steel module

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] Example 1: 3Cr2NiMnMo large-scale pre-hardened plastic mold steel module with dimensions of 1020mm (thickness) × 1220mm (width) × 2620mm (length). After forging, it is cooled by strong wind for 6 hours, and the temperature control point is reduced to 350°C before air cooling. When the temperature at the temperature control point drops to 250°C, enter the 350°C trolley-type gas furnace for 6 hours and heat it at a heating rate of 50°C / h, after the temperature control point temperature is 750°C, the heating rate is 100°C / h, at 880°C Keep holding for 15 hours to austenitize.

[0024] After the heat preservation is over, the trolley is lifted out and cooled by strong wind for 5 hours. The temperature at the temperature control point drops to 350°C and then air-cooled to room temperature. Afterwards, it is tempered at 560°C for 30 hours; finally, the surface hardness of the module is adjusted to 33±2HRC, and the crystal grain size is 6-7.

Embodiment 2

[0025] Example 2: 3Cr2MnMo large-scale pre-hardened plastic mold steel module with dimensions of 300mm (thickness) × 790mm (width) × 3500 (length) mm. After forging, it is cooled by strong wind for 4 hours, and the temperature control point is reduced to 350°C and then air-cooled When the temperature at the temperature control point drops to 250°C, enter the 350°C trolley-type gas furnace for 5 hours and then heat it at a heating rate of 50°C / h. After the temperature control point temperature is 750°C, the heating rate is 100°C / h, at 890 Austenitize at ℃ for 13 hours.

[0026] After the heat preservation, the trolley was lifted out and cooled by strong wind for 4 hours. The temperature at the temperature control point was reduced to 350°C and then air-cooled to room temperature. Afterwards, it is tempered after holding at 560℃ for 24 hours; finally adjust the surface hardness of the module to 30±2HRC and the grain size to 7-8.

Embodiment 3

[0027] Example 3: 10Ni2MnCuAl large-scale pre-hardened plastic mold steel module, the external dimension is 1100mm (thickness) × 1120mm (width) × 2600mm (length), after forging, controlled strong wind cooling for 8 hours, temperature control point reduced to 350 ℃ and then air cooling, When the temperature at the temperature control point drops to 250°C, enter the 350°C trolley-type gas furnace for 7 hours and heat it at a heating rate of 50°C / h, and after the temperature control point temperature is 750°C, the heating rate is 100°C / h, at 880°C Keep holding for 18 hours to austenitize.

[0028] After the heat preservation, the trolley was lifted out and cooled by strong wind for 6 hours. The temperature at the temperature control point dropped to 350°C and then air-cooled to room temperature. Afterwards, the temperature is kept at 560°C for 33 hours for tempering; finally, the surface hardness of the module is adjusted to 36±2HRC, and the grain size is 7-8.

[0029] For the locati...

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 relates to an organization control method of a large-size pre-hardening type plastic die steel module for manufacturing plastic products, belonging to the technical field of metallographical organization structure control of alloy steel heat treatment. Aiming at multiple large-size pre-hardening type plastic die steel containing carbon, chromium, manganese and molybdenum or the large-size pre-hardening type plastic die steel containing a small amount of elements of copper, nickel, aluminum, boron, and the like, after steel ingots are forged into a module, cooling is controlled according to the phase change characteristics of the steel, and then heat is preserved in a low-temperature furnace to ensure that the austenite of the module is sufficiently converted; the module is heated again at a proper speed, and after complete austenite, the cooling is controlled; after the temperature of the surface of the module is reduced to 350-200 DEG C, slow cooling is carried out to obtain a bainite or bainite and martensite mixed organization, and the grain size is 5-8 grades; and finally, tempering is carried out within a temperature range of 300-600 DEG C, the hardness is adjusted into a range of 28-38 HRC, and the section hardness difference is smaller than +/-2HRC.

Description

Technical field [0001] The invention relates to a method for controlling the structure of a large pre-hardened die steel module used in the manufacture of plastic products, and belongs to the technical field of heat treatment metallographic structure control of alloy steel. Background technique [0002] Pre-hardened plastic mold steel is generally alloyed by adding an appropriate amount of alloying elements such as Cr, Mn, Mo, etc. on the basis of 0.2 to 0.5 wt% carbon steel, and some also adding Cu, Ni, Al, B At present, 3Cr2MnMo, 3Cr2NiMnMo and 10Ni2MnCuAl are widely used at home and abroad. The general manufacturing method of pre-hardened plastic mold steel is to obtain martensite or martensite + see-tensite structure after the ingot is forged into a module, and finally tempered to adjust the hardness in the range of 28-38HRC, so that Machining to make molds. [0003] The manufacture of large pre-hardened plastic mold steel requires large steel ingots. Due to the huge steel in...

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): C21D6/00C21D1/18C21D1/84C21D11/00
Inventor 吴晓春党卫东吴俊闵永安汪宏斌图而兴
Owner SHANGHAI UNIV
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