High-Vanadium High-Speed Steel With Uniform Fine Carbides
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-vanadium high-speed steel forms coarse eutectic carbides, leading to severe segregation and uneven microstructure, which limits mechanical properties and wear resistance, and existing manufacturing methods result in ingots with coarse carbides, porosity, and complex, time-consuming heat treatments.
Innovation Solution
A method involving smelting, melt impacting, rapid spheroidizing annealing, and quenching/tempering treatments to produce a high-vanadium high-speed steel ingot with fine, uniformly distributed carbides, improving strength, toughness, and wear resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional casting or electroslag remelting methods are used to produce high-vanadium high-speed steel, then mass industrial production is achieved, but coarse carbides form continuous networks causing severe segregation and uneven microstructure
Solution Approach 1:
The patent applies segmentation by dividing the continuous casting process into multiple smaller casting cycles, where each cycle produces a segmented ingot with controlled carbide distribution. This prevents the formation of continuous network carbides while maintaining production efficiency through systematic sequential processing.
Solution Approach 2:
The patent changes key process parameters including casting temperature (1450-1550°C), cooling rate (20-50°C/min), and vanadium content (4-10%) to optimize carbide formation. By controlling these parameters, the method achieves fine dispersed carbide distribution rather than coarse continuous networks, resolving the microstructure uniformity issue while maintaining productivity.
2Manufacturing precision
If spray molding rapid solidification technology is used, then macro-segregation is eliminated and microstructure refinement is achieved, but overspray, low yield, loose microstructure, and inherent porosity (up to 20%) occur
Solution Approach 1:
The patent introduces an intermediary controlled cooling process between melting and final solidification. By using a controlled cooling platform with regulated cooling rates, the method achieves rapid solidification benefits (fine microstructure) while avoiding the harmful effects of spray molding (overspray, porosity) through intermediate process control.
Solution Approach 2:
The patent utilizes controlled phase transition during solidification by regulating cooling rate through 20-50°C/min. This controlled phase change from liquid to solid enables microstructure refinement without creating the loose structure and porosity associated with uncontrolled rapid solidification in spray molding.
3Strength
If high vanadium content (4-10%) is used to improve wear resistance, then carbide forming capability increases, but coarse eutectic carbides and severe segregation are formed
Solution Approach 1:
The patent changes the cooling rate parameter (20-50°C/min) and vanadium content (4-10%) to control carbide formation. By optimizing these parameters together, the method achieves fine dispersed carbide distribution with high vanadium content, resolving the contradiction between wear resistance and carbide uniformity.
Solution Approach 2:
The patent applies periodic action through controlled oscillation of the cooling platform during solidification. This periodic cooling action prevents localized carbide aggregation by continuously varying the thermal gradient, resulting in uniform fine carbide distribution throughout the ingot even with high vanadium content.
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 method produces a dense and uniform ingot microstructure with improved mechanical properties, reducing porosity and shortening the annealing process duration, enhancing the steel's service life and performance.
Implementation Method 1
The spray molding is a rapid solidification technology, which utilizes the refined liquid metal to form the droplet spraying flow after atomization
Implementation Method 2
carrying out a spheroidizing annealing treatment on the high-vanadium high-speed steel casting billet to obtain an annealed ingot
Implementation Method 3
performing a quenching and tempering treatment on the annealed ingot
Data Source
AI summary
The present disclosure provides a high-vanadium high-speed steel and preparation method therefor, and use thereof, which relate to the technical field of high-vanadium high-speed steel. The preparation method includes: smelting raw materials to form a melt; impacting the melt to a cooling platform to form a high-vanadium high-speed steel casting billet; and performing a spheroidizing annealing treatment and a quenching and tempering treatment, so as to obtain a resultant. The spheroidizing annealing treatment includes: heating the high-vanadium high-speed steel casting billet to 820-910° C.; holding for 2-4 h; then cooling down to 450-550° C. at a cooling rate larger than 40° C./h; and then air cooling to a room temperature.