Al-Si-Fe Coating Cover Layer for Tool Wear Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aluminium-based coatings for steel sheets or strips face issues such as reduced furnace roller service life, high tool wear, non-uniform surface formation, and welding problems due to reaction with ceramic rollers and abrasive nature during hot-forming and cold-forming processes.
Innovation Solution
A cover layer containing aluminium oxide and/or aluminium hydroxide is applied through plasma oxidation or anodic oxidation, produced in a melting bath with specific Si and Fe content, which acts as a separation layer between the coat and ceramic rollers, reducing wear and abrasion, and is treated with hot water or steam to enhance properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an aluminium-based coat is applied by hot-dipping for corrosion protection, then corrosion resistance is improved, but tool wear and abrasion increase during forming processes
Solution Approach 1:
The patent applies a composite coating structure consisting of an aluminium-based coat (Al-Si-Fe alloy) combined with a cover layer containing aluminium oxide and/or aluminium hydroxide. This composite structure provides both corrosion protection from the aluminium-based coat and reduced tool wear from the oxide/hydroxide cover layer, resolving the contradiction between corrosion resistance and tool wear.
Solution Approach 2:
The cover layer containing aluminium oxide and/or aluminium hydroxide acts as an intermediary between the aluminium-based coat and the forming tools. This intermediate layer reduces direct contact and abrasion between the metallic coat and tools, thereby reducing tool wear while maintaining the corrosion protection function of the underlying aluminium-based coat.
2Reliability
If an aluminium-based coat is applied by hot-dipping, then corrosion protection is improved, but furnace roller service life is reduced due to reaction with ceramic rollers
Solution Approach 1:
The cover layer containing aluminium oxide and/or aluminium hydroxide serves as a protective intermediary between the aluminium-based coat and the ceramic furnace rollers. This layer prevents direct chemical reaction between the metallic coating and the ceramic rollers, thereby extending furnace roller service life while maintaining the corrosion protection benefits of the aluminium-based coat.
Solution Approach 2:
The patent converts the potential harmful reaction between aluminium and ceramic rollers into a beneficial oxide layer formation. By controlling oxidation to form a stable aluminium oxide/hydroxide cover layer, the inherently reactive aluminium is transformed into a stable, non-reactive protective layer that prevents further harmful reactions with furnace rollers.
3Reliability
If an aluminium-based coat is applied by hot-dipping, then corrosion resistance is improved, but surface uniformity deteriorates due to non-uniform surface formation
Solution Approach 1:
The patent optimizes the composition parameters of the aluminium-based coat, specifically controlling the Si content at 8-12 wt.% and Fe content at 1-4 wt.%, to achieve more uniform surface formation during hot-dipping. Additionally, the oxidation process parameters are controlled to form a uniform cover layer of aluminium oxide and/or aluminium hydroxide, thereby improving surface uniformity while maintaining corrosion resistance.
4Reliability
If an aluminium-based coat is applied by hot-dipping, then corrosion protection is improved, but welding quality deteriorates due to welding problems
Solution Approach 1:
The patent creates a coating structure with different local properties: the aluminium-based coat provides corrosion protection, while the cover layer containing aluminium oxide and/or aluminium hydroxide provides improved weldability. This local differentiation allows the coating to exhibit different qualities in different regions, resolving the contradiction between corrosion protection and welding quality.
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 cover layer significantly reduces tool wear, maintains surface integrity, prevents welding issues, and enhances corrosion resistance, allowing for improved hot-forming and cold-forming processes with reduced maintenance and increased durability.
Implementation Method 1
the coating is subjected to plasma oxidation and/or a hot water treatment and/or a steam treatment and/or an anodic oxidation, in which the coating is oxidised on the surface with oxides or hydroxides being formed
Implementation Method 2
the coating is subjected to plasma oxidation and/or a hot water treatment and/or a steam treatment and/or an anodic oxidation, in which the coating is oxidised on the surface with oxides or hydroxides being formed
Implementation Method 3
the coating is subjected to plasma oxidation and/or a hot water treatment and/or a steam treatment and/or an anodic oxidation, in which the coating is oxidised on the surface with oxides or hydroxides being formed
Data Source
AI summary
In an aluminium-based coating for steel sheets or steel strips, the coating includes an aluminium-based coat applied in a hot-dip coating method, a covering layer containing aluminium oxide and/or hydroxide being arranged on the coat. The covering layer is produced by plasma oxidation and/or hot water treatment at temperatures of at least 90° C., advantageously at least 95° C., and/or steam treatment at temperatures of at least 90° C., advantageously at least 95° C. Alternatively, the covering layer containing aluminium oxide and/or hydroxide can be produced by anodic oxidation, the coat being produced in a molten bath with a Si content of between 8 and 12 wt. %, and an Fe content of between 1 and 4 wt. %, the remainder being aluminium.