A kind of normalizing liquid for steel castings and normalizing cooling process for steel castings

A cooling process and technology for steel castings, applied in the direction of quenching agent, manufacturing tools, heat treatment equipment, etc., can solve the problems of high viscosity, increase investment cost, increase the consumption of uniform cooling medium belt, etc., to achieve good fluidity and cooling speed. Fast and avoids uneven effects

Active Publication Date: 2018-06-22
NANJING KERUN LUBRICANTS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the concentration of the uniform cooling medium is relatively high, and the uniform cooling characteristics can only be obtained at a concentration of more than 20%. However, a higher concentration increases the initial investment cost on the one hand; Belt consumption of uniform cooling medium

Method used

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  • A kind of normalizing liquid for steel castings and normalizing cooling process for steel castings
  • A kind of normalizing liquid for steel castings and normalizing cooling process for steel castings
  • A kind of normalizing liquid for steel castings and normalizing cooling process for steel castings

Examples

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Effect test

example 1

[0029] Example 1: ZG25MnNi mining machine rocker arm, workpiece size: maximum length 2.8m, maximum width 0.9m, maximum height 1m. Heat treatment technical requirements: hardness ≥ 190HB, yield ratio ≥ 0.8, impact energy Akv ≥ 60J / cm 2 . After normalizing, the workpiece is directly put into 15% normalizing liquid for immersion cooling, and compared with the traditional air cooling method. The cooling process of the workpiece is carried out in the way of radiation and convection, with proper stirring during cooling, the temperature of the workpiece outlet liquid is controlled below 200 ° C, and then transferred to the tempering furnace for high temperature tempering. The stock solution of normalizing liquid is prepared according to the following formula: polyvinyl alcohol accounts for 10%, sodium polyacrylate accounts for 20%, sodium carboxymethylcellulose accounts for 0.6%, triethanolamine 2% (rust inhibitor), high-carbon alcohols disinfectant Foam agent 1%, isothiazolinone 1...

example 2

[0034] Example 2: ZG25CrNiMo box, original heat treatment process: conventional normalizing + high temperature tempering, but normalizing is cooled by traditional air cooling, the workpiece structure is coarse ferrite + pearlite, and the content of granular bainite is very small. In order to improve the structure of the workpiece and increase the content of granular bainite, after the normalizing heat preservation of the workpiece is completed, it is changed to directly immerse in the normalizing liquid with a concentration of 10% to cool, and then with proper stirring, the temperature of the workpiece liquid is controlled below 200 ℃, and then Transfer to tempering oven to keep warm. The stock solution of normalizing liquid is prepared according to the following formula: polyvinyl alcohol accounts for 5%, sodium polyacrylate accounts for 10%, sodium carboxymethylcellulose accounts for 0.5%, triethanolamine 2% (rust inhibitor), high-carbon alcohols disinfectant Foam agent 0.5%...

example 3

[0036] Example 3: ZG42CrMo traveling wheel, in order to improve the original casting structure and refine the grain, normalizing treatment is required. The original normalizing process adopts the traditional air cooling method, and the slow cooling rate increases the content of pro-eutectoid ferrite in the workpiece structure, and it is distributed in a network shape, and the grains are relatively coarse. In order to improve the structure of the workpiece, the current process is changed to: after the normalizing heat preservation is completed, use 20% concentration of normalizing liquid for immersion cooling, and the workpiece is cooled by radiation and convection. fire treatment. The stock solution of normalizing liquid is prepared according to the following formula: polyvinyl alcohol accounts for 15%, sodium polyacrylate accounts for 25%, sodium carboxymethylcellulose accounts for 0.5%, triethanolamine 3% (rust inhibitor), high-carbon alcohols disinfectant Foam agent 1%, is...

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Abstract

The invention relates to a steel casting normalizing solution and a steel casting normalizing cooling technique, belonging to the technical field of heat treatment of steel castings. The normalizing solution is a high-molecular polymer water solution. The high-molecular polymer water solution is composed of the following components in percentage by weight: 5-15% of polyvinyl alcohol, 10-25% of sodium polyacrylate, 0.5-1.0% of sodium carboxymethyl cellulose, 3-6% of additive and the balance of water. The steel casting normalizing solution and steel casting normalizing cooling technique improve the cooling uniformity, inhibit the pro-eutectoid phase, and solve the technical problems of poor mechanical anisotropy, poor impact toughness and low yield-tensile ratio.

Description

technical field [0001] The invention relates to a normalizing liquid for steel castings and a normalizing cooling process for steel castings, belonging to the technical field of heat treatment for steel castings. Background technique [0002] Low-alloy steel castings have low alloy element content and poor hardenability, and are mostly used to make box-type parts. After casting steel castings, the casting structure is coarse, reticular ferrite and Widmanstatten structure often appear, and there are obvious mixed crystals, resulting in poor impact toughness, low hardness, low tensile strength and yield strength of the workpiece. Bending and fracture failures often occur during the process. With the conventional normalizing air cooling process, due to the slow cooling rate between the two-phase regions, the pro-anatectoid ferrite phase is precipitated, the mixed crystal phenomenon cannot be improved, the hardness of the workpiece is reduced, and the toughness is deteriorated....

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C21D1/28C21D1/60
CPCC21D1/28C21D1/60C21D2211/002
Inventor 牛文明左永平聂晓霖孙清汝
Owner NANJING KERUN LUBRICANTS
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