Composite Additive for Core-Shell Inclusions in Steel
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for controlling non-metallic inclusions in steel are complex, costly, and often ineffective in improving the mechanical and corrosion properties of steel, particularly for applications requiring high fatigue resistance and local corrosion resistance.
Innovation Solution
A composite additive with a core-shell structure, composed of Fe, Zr, Ti, Mg, and RE elements, is introduced to form fine, spheroidized, and dispersed inclusions, which significantly improve the plasticity, toughness, and corrosion resistance of steel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional deoxidation methods (Al, Mn) are used, then deoxidation is achieved, but Al2O3 inclusions form which cause nozzle blockage, surface defects, and reduced mechanical properties
Solution Approach 1:
The patent changes the chemical composition parameters by introducing a composite additive containing Zr (5-11%), Ti (14-26%), Mg (11-19%), and RE (4-10%) elements with specific mass ratios. This transforms the deoxidation process to form different inclusion compounds (ZrO2, TiO2, MgO, and their complex oxides) instead of Al2O3, fundamentally altering the inclusion characteristics to be finer, more spherical, and less harmful
Solution Approach 2:
The patent uses a composite additive material containing multiple elements (Fe-Zr-Ti-Mg-RE) that work synergistically. The composite nature allows formation of complex oxide inclusions with combined properties from different elements, achieving fine dispersion, spherical morphology, and improved steel quality that cannot be obtained with single-element deoxidizers
2Manufacturing precision
If existing inclusion control methods are applied, then some purification is achieved, but the process becomes complex and costly with limited improvement in mechanical and corrosion properties
Solution Approach 1:
The patent merges multiple functions into a single composite additive: deoxidation, inclusion modification, grain refinement, and corrosion resistance enhancement are all achieved through one additive rather than multiple separate treatments. This simplifies the smelting process while improving steel quality across multiple parameters simultaneously
3Strength
If traditional additives are used, then basic deoxidation is achieved, but fine, spheroidized, and dispersed inclusion structure is not formed, limiting toughness and fatigue resistance
Solution Approach 1:
The patent promotes formation of spherical inclusion morphologies through the composite additive. The Zr, Ti, Mg, and RE elements facilitate oxidation and spheroidization of inclusions, transforming them from irregular shapes to spherical forms that reduce stress concentration and improve steel toughness and fatigue resistance
Solution Approach 2:
The patent achieves fine segmentation of inclusions through the composite additive, creating numerous small, dispersed particles rather than large aggregates. The specific element ratios promote nucleation of many fine inclusions distributed uniformly throughout the steel matrix, improving mechanical properties by reducing local stress concentrations
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 composite additive effectively refines the grain structure, improves the toughness and fatigue resistance of steel, and enhances its corrosion resistance in neutral and seawater environments, making it suitable for various steel applications with stringent inclusion shape requirements.
Implementation Method 1
the mass percentage content of Zr element, Ti element, Mg element and RE element satisfies a formula: (Ti+Mg+RE)/Zr＝4-8
Data Source
AI summary
A composite additive for forming inclusions with a core-shell structure, a preparation method and a smelting method are provided. The composite additive includes the following chemical components by mass percentage: Fe: 41-59%, Zr: 5-11%, Ti: 14-26%, Mg: 11-19%, and RE: 4-10%, in which the mass percentage content of Zr element, Ti element, Mg element and RE element satisfies a formula: (Ti+Mg+RE)/Zr=4-8. The composite additive for forming inclusions with a core-shell structure has the characteristics of fineness, spheroidization and obvious dispersion effect. This type of inclusions has a bulk modulus similar to that of the iron matrix, which can significantly improve the plasticity, toughness, fatigue resistance, local corrosion resistance, welding performance, cold bending performance, etc. of steel materials, suitable for steel types with strict requirements on the shape of inclusions, such as marine steel, pipeline steel, container steel, cold heading steel, tool and die steel, etc.