Water-Based Coolant for Metal Quenching

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Solution Overview

Problem

Water-based coolants used for quenching metal components often result in uneven cooling and corrosion of metal materials, while oil-based coolants provide insufficient cooling for large or poorly hardenable components, and saline solutions lead to rapid rust formation and corrosion.

Innovation Solution

A water-based coolant formulation containing inorganic acid salts such as carbonate, phosphate, and metal corrosion inhibitors like benzotriazole, along with a bactericide, to enhance cooling performance and prevent metal corrosion, with specific concentration ranges for optimal effectiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If water-based quenchant is used, then cooling performance is improved, but uneven cooling occurs and quenching cracks may be caused

Engineering Contradiction:
Improvecooling speedVSAvoiduniformity of cooling
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The invention changes the chemical composition parameters of the water-based quenchant by adding specific inorganic salts (carbonate, hydrogen carbonate, sesquicarbonate, phosphate, borate, molybdate, or tungstate) to modify the cooling characteristics. This allows the coolant to maintain high cooling speed while reducing the steam film stage duration, thereby improving uniformity of cooling and preventing quenching cracks.

Inventive Principle:
Principle #35Parameter changes

2Speed

If saline solution is used as quenchant, then uneven-cooling resistance is improved and cooling performance is enhanced, but rust forms rapidly and severe corrosion of equipment occurs

Engineering Contradiction:
Improvecooling speedVSAvoidcorrosion and rust
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The invention converts the harmful corrosive effect of inorganic salts into a beneficial cooling effect. By using inorganic salts at controlled concentrations (1-20 mass%), the coolant achieves high cooling performance similar to saline solutions while the addition of corrosion inhibitors prevents the rust and corrosion problems. The harmful corrosion is transformed into useful cooling enhancement.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The invention introduces corrosion inhibitors as intermediary substances that mediate between the inorganic salts and metal components. These inhibitors form protective films on metal surfaces, preventing direct contact between corrosive inorganic salts and metal, thereby eliminating rust formation and equipment corrosion while maintaining the cooling benefits of inorganic salts.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If oil-based quenchant is used, then quenching distortion is reduced and quenching cracks are avoided, but cooling speed is slow and cooling performance is insufficient

Engineering Contradiction:
Improveuniformity of coolingVSAvoidcooling speed
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The invention creates a composite water-based quenchant system that combines water, inorganic salts, and corrosion inhibitors to achieve properties similar to oil-based coolants. The composite formulation provides both high cooling speed (like water) and uniform cooling (like oil), eliminating the need to choose between the two traditional options.

Inventive Principle:
Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The coolant achieves high cooling performance without causing metal corrosion, making it suitable for quenching or cutting metal materials, and exhibits excellent antibacterial properties, maintaining effectiveness even at elevated temperatures.

Implementation Method 1

a water-based coolant contains: at least one inorganic acid salt selected from among carbonate, hydrogen carbonate, sesquicarbonate, phosphate, borate, molybdate and tungstate; and a metal corrosion inhibitor

Methodology Applied
Scientific EffectMetal corrosion inhibition:

Implementation Method 2

The water-based coolant further contains a bactericide

Methodology Applied
Scientific EffectBactericide action:

Data Source

PatentUS10421924B2Water-based coolant
Publication Date: 2019.09.24 IDEMITSU KOSAN CO LTD

AI summary

Disclosed herein is a method of using a water-based coolant for quenching or cutting a metal material. The water-based coolant is formed of: water; at least one inorganic acid salt selected from the group consisting of a carbonate, a hydrogen carbonate, a sesquicarbonate, a phosphate, a borate, a molybdate and a tungstate; a metal corrosion inhibitor; and optionally at least one of a bactericide, a water-soluble rust inhibitor, an antioxidant and a detergent dispersant.