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

Heat treatment method for 18CrNiMo7-6 steel

A heat treatment method and steel technology, applied in heat treatment furnaces, heat treatment equipment, furnaces, etc., can solve the problems of easy spheroidization of pearlite, slow cooling process, low hardness of steel, etc., to facilitate cutting and sawing, and facilitate machining , Furnace gas atmosphere consistent effect

Pending Publication Date: 2020-08-11
DAYE SPECIAL STEEL CO LTD
View PDF6 Cites 3 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

When this process is carried out, after the material is austenitized, the cooling process is slow, and the formed pearlite is very easy to spheroidize, so that the final structure is ferrite + granular pearlite, which cannot meet the requirements of lamellar pearlite in 18CrNiMo7-6 steel. requirements, and the hardness of the steel obtained by the existing heat treatment method is low, the hardness is below 180HBW, and the steel with this structure and hardness is prone to sticking to the knife during the sawing process

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 method for 18CrNiMo7-6 steel
  • Heat treatment method for 18CrNiMo7-6 steel
  • Heat treatment method for 18CrNiMo7-6 steel

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0048] This embodiment is a heat treatment method for 18CrNiMo7-6 steel.

[0049] According to mass percentage, the chemical composition of the above 18CrNiMo7-6 steel is: carbon 0.18%, silicon 0.25%, manganese 0.70%, phosphorus and sulfur both 0.015%, chromium 1.6%, nickel 1.5%, molybdenum 0.30%; the rest is Fe and unavoidable impurities.

[0050] The annealing treatment that above-mentioned heat treatment method comprises comprises the following steps:

[0051] First, the 18CrNiMo7-6 round bar forged from the 18CrNiMo7-6 steel ingot is heated up at a rate of 80°C / h to the target temperature of 890°C, and then the first heat preservation treatment is carried out at this temperature for 1.5h / 100mm, and then the wind is carried out. Cold treatment (cooling rate 200°C / h) to the target temperature of 630±10°C, and then conduct a second heat preservation treatment at this temperature for 10h / 100mm, and then cool to room temperature with the furnace to obtain an annealed 18CrNiMo7...

Embodiment 2

[0056] In the heat treatment method of the 18CrNiMo7-6 steel product of the present embodiment, the chemical composition of the 18CrNiMo7-6 steel product is identical with embodiment 1; The mode that equipment, fuel, and round rods adopted in the heat treatment process are piled up on the hearth are all identical with embodiment 1, The annealing treatment of heat treatment includes the following steps:

[0057] First, the 18CrNiMo7-6 round bar forged from the 18CrNiMo7-6 steel ingot is heated up at a rate of 80°C / h, and the temperature is raised to the target temperature of 890°C, and then the first heat preservation treatment is carried out at this temperature for 1.5h / 100mm, and then Air cooling (cooling rate 200°C / h) to the target temperature of 650°C, and then conduct a second heat preservation treatment at this temperature for 10h / 100mm, and cool to room temperature with the furnace to obtain an annealed 18CrNiMo7-6 round rod.

[0058] The microstructure of the 18CrNiMo7-...

Embodiment 3

[0061] In this embodiment, except that the partial annealing process of the round bar is different from that of Example 1, other processes and performance testing methods are the same as those of Example 1. The only difference between the annealing process of this embodiment and that of Example 1 is: The cooling method for the temperature to drop to the second heat preservation temperature is air cooling (cooling rate is 100° C. / h). The microstructure of the annealed bar is ferrite (F) + lamellar pearlite (P), the flake pearlite (P) accounts for about 68%, and most of the hardness values ​​in the test samples are in the range of 180-190HBW Inside.

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 method for 18CrNiMo7-6 steel. The method is used for carrying out annealing treatment on a round bar forged by an 18CrNiMo7-6 steel ingot; and in the annealingtreatment, the temperature of the round bar is increased to a first heat preservation temperature and heat preservation is carried out at the first heat preservation temperature, then air cooling iscarried out until a second heat preservation temperature is achieved and heat preservation is carried out at the second heat preservation temperature, and finally cooling is carried out, wherein the first heat preservation temperature is larger than or equal to 800 DEG C, and the second heat preservation temperature is 620-650 DEG C. According to the method, the cooling speed and the heat preservation temperature in isothermal annealing are controlled, so that the 18CrNiMo7-6 steel with ferrite and flaky pearlite structures is obtained, the steel has moderate hardness, the steel is convenientto machine, be subjected to blanking and saw, the cutter sticking phenomenon is avoided, and the yield is increased.

Description

technical field [0001] The invention belongs to the field of heat treatment of special steel materials, and in particular relates to a heat treatment method of 18CrNiMo7-6 steel materials. Background technique [0002] 18CrNiMo7-6 is the grade of EN 10084 surface hardened steel, which is the steel number representation method of the European Committee for Standardization, and its number number is 1.6587. 18CrNiMo7-6 hardened steel is widely used for its good processing performance, mechanical properties and high wear resistance. Suitable for wind power, mine reducer gears, locomotive gears, etc. [0003] 18CrNiMo7-6 is a surface carburized and quenched gear material. The rolled or forged raw materials are generally delivered in the state of ferrite (F) + pearlite (P). In order to obtain the ferrite + pearlite structure, the isothermal annealing process is adopted. The original annealing process is: 870°C ± 10°C heat preservation → furnace cooling to 690°C → slow cooling to ...

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): C21D1/26C21D1/34C21D6/00C21D9/00C22C38/02C22C38/04C22C38/44
CPCC21D1/26C21D1/34C21D6/004C21D9/0075C21D2211/005C21D2211/009C22C38/002C22C38/02C22C38/04C22C38/44
Inventor 王占忠李博鹏史啸峰柳萍郑文超王震李波罗时杰胡梦頔
Owner DAYE SPECIAL STEEL CO LTD
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