Heat-treating process for hot-working die steel forgings

A technology of hot-working die steel and die steel, which is applied in the field of heavy industrial heat treatment, can solve the problems of high cost and limited performance improvement, and achieve the effect of improving performance, meeting performance requirements and increasing temperature

Inactive Publication Date: 2015-04-08
TONGYU HEAVY IND
View PDF4 Cites 18 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In order to solve the problems of high cost and limited performance improvement in the heat treatment process of hot work die steel forgings in the prior art, the present invention provides a hot work method with low cost and greatly improved various properties of hot work die steel forgings. Heat Treatment Process of Die Steel Forgings

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-treating process for hot-working die steel forgings
  • Heat-treating process for hot-working die steel forgings
  • Heat-treating process for hot-working die steel forgings

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] Example 1: 5CrNiMo die steel heat treatment

[0035] Increase the cooling rate, increase the depth of the hardened layer, so that the mechanical properties meet the customer's requirements, and the workpiece is subjected to the following heat treatment tests:

[0036] 1. Increase the spheroidizing annealing process before quenching: the forging is loaded in a furnace at ≤400°C, raised to 820°C at a speed of ≤60°C / h and kept for 8 hours, then cooled to 760°C at a rate of ≤15°C / h for 15 hours, and then Furnace cooling to 400°C at a rate of ≤10°C / h;

[0037] 2. Quenching: Furnace the forgings at ≤400°C at a rate of ≤60°C / h to 650°C, hold for 2 hours, then raise the temperature to 880°C at a rate of ≤80°C / h, and hold for 10 hours to make the workpiece fully quenched tempering;

[0038] 3. Cooling: raise the water temperature to 60°C, keep the workpiece at 860°C, and after 12 hours of heat preservation, take the workpiece out of the furnace with a crane, and then cool it ...

Embodiment 2

[0064] Example 2: Heat treatment of H13 die steel

[0065] Increase the cooling rate, increase the depth of the hardened layer, so that the mechanical performance requirements meet the customer's requirements, and the workpiece is subjected to the following heat treatment tests:

[0066] 1. Increase the spheroidizing annealing process before quenching: the forging is loaded in the furnace at ≤400°C, raised to 860°C at a speed of ≤60°C / h for 12 hours, cooled to 760°C at a rate of ≤30°C / h for 35 hours, and then press ≤30℃ / h speed furnace cooling to 240℃;

[0067] 2. Quenching: Furnace the forgings at ≤400°C, raise the temperature to 680°C at a rate of ≤60°C / h for 3 hours, then raise the temperature to 1050°C at a rate of ≤80°C / h, and hold for 16 hours to make the workpiece fully tempering;

[0068] 3. Cooling: Raise the water temperature to 40°C, take the workpiece out of the furnace with a crane, and then use air cooling for 2.5 minutes-water for 8 minutes-empty for 1 minut...

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 belongs to the technical field of heat treatment of heavy industry, and particularly relates to a heat-treating process for hot-working die steel forgings. The heat-treating process comprises the following steps: spheroidizing and annealing, quenching, cooling and tempering. The heat-treating process is suitable for 5CrNiMo die steel or H13 die steel; spheroidizing and annealing heat treatment is added before quenching, so that the preheating treatment structure of a workpiece is transformed into globular pearlite and cementite; the risk of a quenching crack of the workpiece is reduced; the quenching temperature is improved; austenization is relatively full; and the temperature of a quenching medium is improved. Warm water at 40-60 DEG C is adopted as the quenching medium, so that the performance of the workpiece is improved under the premise that no crack of the workpiece is ensured. Through combination of three improvement points, the performance of the workpiece, especially the impact strength is obviously improved; and the performance requirements are met.

Description

technical field [0001] The invention belongs to the technical field of heavy industrial heat treatment, and in particular relates to a heat treatment process for hot work die steel forgings. Background technique [0002] In recent years, with the continuous development of the heavy industry, the requirements for the performance of forgings are getting higher and higher, such as 5CrNiMo, H11, H13 and other hot work die steels, which have strict requirements on hardness and mechanical properties, especially impact properties. [0003] In the prior art, annealing treatment is also used in the heat treatment process of hot work die steel forgings. For example, the Chinese patent with the publication number CN1540001A discloses an isothermal spheroidizing annealing process for H13 steel. Before 4 hours, first heat up the furnace to 680°C for 1 hour, and then cool to 710-740°C with the furnace before air-cooling below 500°C, and then keep it warm for 3-4 hours. The service li...

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): C21D6/00C21D1/18C21D1/32
Inventor 司兴奎刘殿山呙文武颜廷勇燕友增
Owner TONGYU HEAVY IND
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