Forging waste heat isothermal normalizing device and method

A technology of isothermal normalizing and forging waste heat, applied in the direction of manufacturing tools, heat treatment equipment, heat treatment process control, etc., can solve the problem of lower end-use performance of carburized steel parts, coarse austenite grains, and reduced machining performance of forging billets And other issues

Active Publication Date: 2011-12-21
浙江万能达炉业有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, after long-term research, it has been found that due to the high forging heating temperature, the final forging temperature is also high and the temperature is uneven, so that the austenite grains are relatively coarse and uneven.
Moreover, it is easy to form α-Widmanstenberg structure and unstable structure during subsequent air cooling, which reduces the cutting performance of the forging billet and significantly reduces the end-use performance of the carburized steel product.
Therefore, direct normalizing of the forged billet using the waste heat after forging has not been applied so far due to its poor quality and instability.

Method used

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  • Forging waste heat isothermal normalizing device and method
  • Forging waste heat isothermal normalizing device and method
  • Forging waste heat isothermal normalizing device and method

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0097] 20CrMnTi steel was used for the gear forging billet used in the test, and the actual chemical composition of the batch of forging billets was determined to be wt%: 0.186C, 0.25Si, 1.05Mn, 0.020S, 0.015P, 1.02Cr, 0.15Ti. The effective thickness of the forging (forging billet) is: 30mm; the required hardness is HB165-185, the microstructure is F (ferrite) + P (pearlite), without B (bainite) and M (martensite).

[0098] Enter the actual chemical composition, effective thickness and required hardness of the forged billet into the calculation system of the above formula to obtain:

[0099] Pre-cooling temperature T1=800°C, pre-cooling temperature residence time t1=2min, select pre-cooling speed V 1 =5°C / min;

[0100] Forced cooling speed V 2 =60°C / min, strong cooling temperature T 2 = 610°C;

[0101] isothermal temperature T iso =610°C, isothermal time t iso = 150 min.

[0102] Input the calculated process parameters into the control system of the device and run the d...

example 2

[0104] In this example, the control system in the waste heat isothermal normalizing device of the present invention communicates with the process parameter calculation expert software to directly control the operation of the device after inputting the actual chemical composition, effective thickness and hardness requirements of the forging billet.

[0105] 20CrMnMo (SCM22) steel was selected for the test gear forging billet, and the actual chemical composition of the batch of forging billet was detected as wt%: 0.201C, 0.25Si, 0.65Mn, 0.03S, 0.02P, 1.10Cr, 0.25Mo. The effective thickness of the workpiece (forging billet) is: 30mm; the required hardness is HB160-180, and the microstructure is F+P.

[0106] Enter the actual chemical composition, effective thickness and required hardness of the forged billet into the calculation system of the above formula to obtain:

[0107] Pre-cooling temperature T 1 =810°C, pre-cooling temperature residence time t 1 =(5)min, select the pre-...

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Abstract

The invention provides a method and a device for carrying out isothermal normalizing heat treatment on alloy cemented steel parts utilizing forging waste heat. The method comprises the following steps: after finish forging of a forged steel blank, slowly cooling the forged steel blank from the final forging temperature to a pre-cooling temperature T1 at a pre-cooling rate V1, insulating heat for t1, then rapidly cooling to a forced cooling temperature T2 at a forced cooling rate V2, carrying out isothermic transition at the isothermic temperature of Tiso for isothermic time tiso, and then cooling to room temperature in a random cooling mode. The invention also provides a device for isothermal normalizing of cemented steel parts utilizing forging waste heat, and the device is composed of atransmission mechanism, a slow cooling chamber, a rapid cooling chamber, an isothermal furnace, a control system, a transmission system and process parameter calculation and correction software. The calculated process parameters can be used for precise control and operation of the device, thereby guaranteeing that the normalizing quality of steel parts is superior or at least equal to the heat treatment quality using conventional normalizing and isothermal normalizing.

Description

technical field [0001] The present invention generally relates to heat treatment of mechanical parts, in particular to a device and method for carrying out isothermal normalizing treatment on alloy carburized steel parts by using waste heat after blank forging. Background technique [0002] Machinery manufacturing and equipment industry is an important field of technological development and economic growth, but it is also a production industry with relatively high energy consumption. Taking carburized gears as an example, its manufacturing process is as follows figure 1 As shown, three of them are high-energy-consuming thermal processing processes that require high-temperature heating, namely forging (or rolling), normalizing, and carburizing and quenching. [0003] Normalizing is a heat treatment process, which is mainly used to improve the problem of coarse and uneven grains of carburized steel blanks (hereinafter referred to as forging blanks) after high-temperature forg...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C21D1/28C21D11/00
Inventor 刘云旭王淮朱卫福季长涛刘澄刘威
Owner 浙江万能达炉业有限公司
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