Heating method capable of reducing depth of decarburized layer of GCr15 bearing steel

A heating method and decarburization layer technology, which are applied in heat treatment furnaces, heat treatment equipment, furnaces, etc., can solve the problems of weak oxidizing atmosphere, affecting production efficiency, and poor comprehensive mechanical properties of finished products during heating time.

Inactive Publication Date: 2017-12-12
NANJING IRON & STEEL CO LTD +1
View PDF5 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The thickness of the decarburized layer can be controlled to a certain extent by controlling the heating temperature and holding time, but the comprehensive mechanical properties of the finished product will be poor due to insu

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0013] This embodiment is a heating method for reducing the depth of the decarburization layer of GCr15 bearing steel, comprising the following steps:

[0014] (1) Put the continuous casting billet into the holding furnace for heat preservation, the heat preservation time is 30 minutes, and the heat preservation temperature is 500-510°C, so that the temperature of the continuous casting billet reaches 500-510°C;

[0015] (2) Thermally load the heat preservation billet of step (1) into a walking beam heating furnace, and heat in 4 sections: the temperature of the non-heating section is 680-685°C; the preheating section is 850-860°C; the heating section is divided into two sections, The temperature of the first stage of heating is 1100-1110°C, the heating time is 80-90min, the temperature of the second stage of heating is 1180-1185°C; -1175°C; the heating time from the beginning of the second stage of heating to the end of the second stage of soaking is 170-180min;

[0016] (3)...

Embodiment 2

[0019] This embodiment is a heating method for reducing the depth of the decarburization layer of GCr15 bearing steel, comprising the following steps:

[0020] (1) Put the continuous casting billet into the holding furnace for heat preservation, the heat preservation time is 30 minutes, and the heat preservation temperature is 550-560°C, so that the temperature of the continuous casting billet reaches 550-560°C;

[0021] (2) Thermally load the insulating billet of step (1) into a walking beam heating furnace, and heat in 4 sections: the temperature of the non-heating section is 750-755°C; the preheating section is 890-1000°C; the heating section is divided into two sections, The temperature of the first stage of heating is 1150-1160°C, the heating time is 55-60min, the temperature of the second stage of heating is 1190-1195°C; -1185°C; the heating time from the beginning of the second stage of heating to the end of the second stage of soaking is 150-160min;

[0022] (3) Oxyge...

Embodiment 3

[0025] This embodiment is a heating method for reducing the depth of the decarburization layer of GCr15 bearing steel, comprising the following steps:

[0026] (1) Put the continuous casting billet into the holding furnace for heat preservation, the heat preservation time is 30 minutes, and the heat preservation temperature is 590-600°C, so that the temperature of the continuous casting billet reaches 590-600°C;

[0027] (2) Thermally load the heat preservation billet of step (1) into a walking beam heating furnace, and heat in 4 sections: the temperature of the non-heating section is 870-880°C; the preheating section is 1010-1020°C; the heating section is divided into two sections, The temperature of the first stage of heating is 1180-1190°C, the heating time is 35-40min, the temperature of the second stage of heating is 1215-1220°C; -1210°C; the heating time from the beginning of the second stage of heating to the end of the second stage of soaking is 130-140min;

[0028] (...

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 heating method capable of reducing depth of a decarburized layer of GCr15 bearing steel. The heating method comprises the following steps of: preserving the heat of steel billets for 30 minutes at a temperature of 500-600 DEG C in a heat preserving furnace; feeding the steel billets into a step beam type heating furnace to heat in four stages, wherein the temperature at a pre-heating stage is 850-1020 DEG C, a temperature at a heating stage I is 1100-1190 DEG C, heating time of the heating stage I is greater than 35 minutes, a temperature at a heating stage II is 1180-1220 DEG C, a temperature at a uniform-heating stage I is 1180-1220 DEG C, a temperature at a uniform-heating stage II is 1170-1210 DEG C, and heating time from the heating stage II to the uniform-heating stage II is greater than 130 minutes; introducing oxygen gas in a heating process, wherein oxygen gas flow at the pre-heating stage is 80000-90000 m<3>/h, oxygen gas pressure at the pre-heating stage is 8-9 bar, oxygen gas flow at the uniform-heating stage is 140000-150000 m<3>/h, and oxygen gas pressure at the uniform-heating stage is 14-15 bar. The method effectively shortens the heating time, and reduces the depth of the decarburized layer.

Description

technical field [0001] The invention belongs to the technical field of metal smelting and processing, and relates to a heating method, in particular to a heating method for reducing the depth of decarburization layer of GCr15 bearing steel. Background technique [0002] During the rolling process of steel, the slab needs to be kept at high temperature for a long time in the heating furnace to make the temperature of the slab uniform and the segregated elements uniform, but with the extension of the heating temperature and holding time, the surface of the billet will eventually be oxidized and decarbonization. The decarburization layer on the steel surface will reduce the surface hardness and strength of GCr15 bearing steel, and has a very important impact on its fatigue life. In the relevant national technical standards, strict requirements are also put forward for the thickness of the decarburization layer of bearing steel. In order to Improve its wear resistance and fatig...

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
IPC IPC(8): C21D9/70C21D1/74
CPCC21D9/70C21D1/74
Inventor 李佑河黄贞益王瑞章侯清宇吴旭明杨凯江雁席波沈千成
Owner NANJING IRON & STEEL CO LTD
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