Negative Pressure Updraught Pouring for Thin Casts
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Solution Overview
Problem
Conventional gravity pouring methods face challenges in forming casts with thin thickness due to slow molten steel flow, high energy consumption, refractory material degradation, and inefficiencies in molten steel yield, leading to poor cast quality and increased production costs.
Innovation Solution
A negative pressure updraught pouring method is employed, where a suction pipe connected to a melting furnace draws molten steel upward into a mold cavity through a flow path system, allowing for reduced melting temperature, efficient steel flow, and return of unsolidified steel to the furnace, eliminating the need for an iron bucket and reducing equipment costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If gravitational pouring method is used, then the pouring process is simple, but the molten steel flowing speed is too slow for thin casts
Solution Approach 1:
The patent inverts the conventional pouring direction by making the mold the lower mold instead of the upper mold. Molten steel is poured from above into the lower mold cavity, allowing gravity to accelerate the flow. This inversion resolves the contradiction by maintaining pouring simplicity while significantly increasing flowing speed, enabling successful casting of thin-walled parts below 3.5mm thickness.
2Quantity of substance
If molten steel temperature is increased to 1700°C or higher, then the flowability is improved, but the electricity consumption increases and refractory materials lifespan is shortened
Solution Approach 1:
The patent applies preliminary action by pre-heating the mold cavity and flow path system before pouring. This ensures that the molten steel maintains its temperature and flowability throughout the casting process without requiring excessive heating during melting. The pre-heated mold prevents rapid cooling and solidification, achieving good flowability at lower melting temperatures and reducing electricity consumption.
3Quantity of substance
If molten steel temperature is increased to 1700°C or higher, then the flowability is improved, but the refractory materials will be fused and impurities increase
Solution Approach 1:
The patent changes the temperature parameter by optimizing the melting temperature to be below 1700°C, specifically controlling it within a range that provides sufficient flowability without causing refractory material fusion. This parameter change prevents the harmful effect of oxide impurities while maintaining adequate flowability through the inverted pouring method and pre-heating measures.
4Device complexity
If conventional pouring method is used, then the flow path system is simple, but the molten steel remaining in the flow path system increases and yield ratio cannot be enhanced
Solution Approach 1:
The patent implements continuity of useful action by designing the flow path system to enable complete evacuation of molten steel from the mold cavity. The inverted pouring method allows steel to flow completely into the mold and then be fully discharged through the lower mold's discharge port, minimizing residual steel in the flow path system and significantly improving the yield ratio.
5Manufacturing precision
If the thickness of cast is reduced, then the product precision is improved, but the flowing speed of molten steel becomes slower and quenching speed increases
Solution Approach 1:
The patent uses the inverted pouring method where the lower mold receives molten steel from above, allowing gravity to accelerate the flow. This inversion provides sufficient flowing speed even for very thin casts, preventing premature solidification and enabling successful formation of thin-walled parts with high manufacturing precision.
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
Enables the production of casts with thicknesses below 2.5mm, reduces energy consumption and refractory material loss, enhances cast purity and mechanical properties, increases yield ratio, and simplifies the manufacturing process while lowering production costs.
Implementation Method 1
negative pressure updraught pouring method
Implementation Method 2
the molten steel is poured and casted into a pre-manufactured mold by gravitational effect
Data Source
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AI summary
A negative pressure updraught pouring method is provided, wherein a melting furnace is filled with molten steel and a flat plate with a suction pipe is covered on a top end of the melting furnace with the bottom end of the suction pipe is dipped into the molten steel; a ventilated mold is placed on the flat plate such that a flow path system of the mold is connected with a top end of the suction pipe; and a chamber is covered on the mold and the flat plate, and the air inside the chamber is drawn out to reduce the air pressure inside the chamber and a cavity of the mold, thereby the molten steel inside the melting furnace is sucked into the mold cavity through the suction pipe and the flow path system by the negative pressure formed inside the chamber for forming a cast.