Titanium Casting Mold Corner Cooling Design

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Solution Overview

Problem

The continuous casting of titanium or titanium alloy ingots often results in surface defects due to uneven cooling rates within the mold, leading to excessive growth, breakage, or intrusion of the solidified shell, which increases production costs and reduces yield.

Innovation Solution

A mold with a rectangular cross-section and no bottom section, featuring smaller thermal flux at corner sections compared to face sections, utilizing cooling means such as flow channels and slow-cooling layers to equalize cooling rates, thereby inhibiting surface defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the mold cools the molten metal uniformly, then the solidified shell grows evenly, but the corner sections cool too quickly causing excessive solidified shell growth and surface defects

Engineering Contradiction:
Improvesurface quality of ingotVSAvoidcooling rate at corner sections
Core Design Contradiction:
Manufacturing precisionVSTemperature

Solution Approach 1:

The patent applies local quality by providing different cooling conditions to different regions of the mold. Flow channels are positioned closer to face sections than corner sections, creating localized variations in cooling intensity. This ensures that corner sections cool more slowly than face sections, preventing excessive solidified shell growth at corners while maintaining adequate cooling at faces, thereby resolving the surface quality issue.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the thermal parameters of the mold by varying the distance from the inner peripheral surface to the flow channels at different locations. By adjusting this geometric parameter, the heat extraction rate is modified locally - face sections have shorter distances for faster cooling, while corner sections have longer distances for slower cooling. This parameter variation equalizes the solidified shell thickness across all sections and eliminates surface defects.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If the solidified shell grows excessively at corner sections, then cooling is sufficient, but the shell breaks due to friction during extraction

Engineering Contradiction:
Improvecooling efficiencyVSAvoidintegrity of solidified shell
Core Design Contradiction:
TemperatureVSStrength

Solution Approach 1:

The patent applies local quality by providing different cooling conditions to different regions of the mold. Flow channels are positioned closer to face sections than corner sections, creating localized variations in cooling intensity. This ensures that corner sections cool more slowly than face sections, preventing excessive solidified shell growth at corners while maintaining adequate cooling at faces, thereby resolving the surface quality issue.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the thermal parameters of the mold by varying the distance from the inner peripheral surface to the flow channels at different locations. By adjusting this geometric parameter, the heat extraction rate is modified locally - face sections have shorter distances for faster cooling, while corner sections have longer distances for slower cooling. This parameter variation equalizes the solidified shell thickness across all sections and eliminates surface defects.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If heating power is increased to remelt the solidified shell, then surface defects are reduced, but energy consumption increases significantly

Engineering Contradiction:
Improvesurface quality of ingotVSAvoidenergy consumption of heating device
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent applies preliminary action by preventing the formation of excessive solidified shell at corner sections through controlled cooling rates from the beginning of the casting process. By designing the flow channel distances in advance, the mold inherently maintains appropriate shell thickness without requiring subsequent heating or remelting operations. This preventive approach eliminates surface defects while avoiding additional energy consumption from heating devices.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the thermal parameters of the mold by varying the distance from the inner peripheral surface to the flow channels at different locations. By adjusting this geometric parameter, the heat extraction rate is modified locally - face sections have shorter distances for faster cooling, while corner sections have longer distances for slower cooling. This parameter variation equalizes the solidified shell thickness across all sections and eliminates surface defects.

Inventive Principle:
Principle #35Parameter changes

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 solution effectively reduces surface defects by equalizing the cooling rate of molten metal at corner and face sections, resulting in a more uniform solidified shell and fewer ingot defects.

Implementation Method 1

heat extracted from a mold is large and titanium has low thermal conductivity

Methodology Applied
Scientific EffectHeat extraction: Conduction (thermal)

Implementation Method 2

a cooling means for making a thermal flux at four corner sections of the mold smaller than a thermal flux at four face sections interposed between the corner sections

Methodology Applied
Scientific EffectThermal flux control: Heat Exchanger

Implementation Method 3

a solidified shell grows excessively in the vicinity of the wall surface of a mold

Methodology Applied
Scientific EffectSolidification: Freezing

Implementation Method 4

it is necessary to increase the output of a heating device, increase a heat input to a molten metal surface, and remelt the solidified shell

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 5

In the case of plasma arc melting, heat can hardly be applied to a corner section

Methodology Applied
Scientific EffectPlasma arc melting: Plasma

Data Source

PatentEP2835191B1Mold for continuous casting of titanium or titanium alloy ingot, and continuous casting device provided with same
Publication Date: 2019.06.12 KOBE STEEL LTD
  • EP2835191B1 patent drawingFigure 1
  • EP2835191B1 patent drawingFigure 2
  • EP2835191B1 patent drawingFigure 3(a)~4

AI summary

A mold (2) has a cooling means (21) for having the thermal flux at four corner sections (2a) be smaller than the thermal flux at four face sections (2b). The cooling means (21) has first channels (22a) which are each embedded in the four corner sections (2a) respectively and which channel cooling water, and second channels (22b) which are each embedded in the four face sections (2b) respectively and which channel cooling water. The distance from the inner peripheral surface of the mold (2) to the first channels (22a) is greater than the distance from the inner peripheral surface of the mold (2) to the second channels (22b).