Ultra-High Heat Input Welding Steel via Two-Stage Rolling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ultra-high heat input welding steels require expensive components like nickel and have difficulty in controlling constituent contents, leading to high production costs and reduced efficiency.
Innovation Solution
A two-stage rolling process with controlled single pass reduction rates and total compression ratios, combined with low-temperature cooling, to produce ultra-high heat input welding steel without expensive additives, regulating oxide inclusions and improving mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If expensive components like nickel and calcium magnesium cored wires are added to improve low-temperature toughness under high heat input welding conditions, then the low-temperature toughness is improved, but the production cost greatly increases
Solution Approach 1:
The patent replaces expensive alloying elements (nickel, calcium magnesium cored wires) with inexpensive oxide inclusions (alumina, silica, magnesia) that can be easily removed or controlled through the two-stage rolling process, achieving the same toughness improvement at much lower cost
Solution Approach 2:
The patent changes the approach from chemical composition modification to physical process parameter control, using specific rolling temperatures (900-1000°C for first stage, 800°C or below for second stage) and compression ratios to control oxide inclusion distribution and achieve low-temperature toughness without expensive additives
2Reliability
If alloy compositions are modified to improve steel properties, then the mechanical properties are improved, but the smelting process is prolonged and production efficiency is reduced
Solution Approach 1:
The patent segments the rolling process into two distinct stages with different temperature ranges and reduction rates, allowing oxide inclusions to be controlled and distributed properly without requiring extended smelting time, thus maintaining high production efficiency while achieving improved mechanical properties
Solution Approach 2:
The patent replaces chemical smelting processes (alloying, deoxidation) with mechanical rolling processes to achieve the desired steel properties, using controlled deformation and oxide inclusion distribution during rolling instead of extended chemical reactions during smelting
3Reliability
If conventional welding methods are used for thick steel plates, then the welding quality is maintained, but multiple passes are required and production efficiency is low
Solution Approach 1:
The patent changes the fundamental welding parameter (heat input) from conventional levels to ultra-high levels (500-1500 KJ/cm), enabling single-pass welding of thick steel plates while maintaining quality, thereby dramatically improving production efficiency compared to multi-pass conventional welding
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 steel with excellent mechanical properties and stable low-temperature toughness, reducing production costs and enhancing welding efficiency for large steel structures.
Implementation Method 1
first-stage rolling is recrystallization zone rolling... performing second-stage rolling when the temperature drops to 800° C. or below, wherein the second-stage rolling is non-recrystallization zone rolling
Implementation Method 2
a cooling step: performing cooling after the rolling step is completed
Data Source
AI summary
A preparation method for ultra-high heat input welding steel, and prepared welding steel are provided. A steel plate oxide inclusion beneficial control is used, and low-temperature large-rolling-reduction rolling is also used. The size and distribution of an oxide in a steel plate are regulated and controlled by controlling a rolling process, thereby realizing the preparation of ultra-high heat input welding steel. The method has a low production cost, the production process is easy to control, the operation is simple, the method is suitable for large-scale production, and the mechanical properties and welding heat impact properties of the base material are excellent.