Low-Temperature Weld Metal Composition With Reduced Ni Cost
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing weld metals for Ni-based low temperature steels are expensive due to high Ni content, and reducing Ni while increasing Mn content leads to deteriorated toughness and mechanical properties.
Innovation Solution
A weld metal composition with controlled contents of C, Si, Mn, Ni, and other elements, ensuring a total (Mn+Ni) of 5.0% or more and an fcc ratio of 70% or more, stabilizing the austenite phase to maintain toughness while reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the Ni content is increased to secure toughness in low-temperature, then the toughness is improved, but the cost increases significantly
Solution Approach 1:
The patent changes the chemical composition parameters by reducing Ni content from 70% to 1.0-30.0% and increasing Mn content to 4.1-30.0%, while controlling other alloying elements (Cr: 0-20.0%, Mo: 0-10.0%, Nb: 0-1.000%, Ti: 0-0.100%, V: 0-1.00%, Al: 0-0.100%) to maintain austenite phase stability and achieve low-temperature toughness at reduced cost
Solution Approach 2:
The patent creates a composite alloying strategy combining Mn (4.1-30.0%), Ni (1.0-30.0%), Cr (0-20.0%), Mo (0-10.0%), Nb (0-1.000%), Ti (0-0.100%), V (0-1.00%), and Al (0-0.100%) where Mn serves as the primary austenite stabilizer replacing expensive Ni, while other elements work synergistically to maintain mechanical properties and phase stability
2Ease of manufacture
If the Ni content is reduced and Mn content is increased to reduce cost, then the cost decreases, but the toughness deteriorates
Solution Approach 1:
The patent optimizes the Mn content parameter to 4.1-30.0% (significantly higher than conventional weld metals) to compensate for reduced Ni, while simultaneously controlling Cr (0-20.0%), Mo (0-10.0%), Nb (0-1.000%), Ti (0-0.100%), V (0-1.00%), and Al (0-0.100%) to maintain austenite phase stability and prevent toughness deterioration
Solution Approach 2:
The patent introduces Cr, Mo, Nb, Ti, V, and Al as intermediary elements that work synergistically with Mn to stabilize the austenite phase and enhance mechanical properties, allowing Mn to effectively replace Ni without sacrificing toughness
3Ease of manufacture
If only Mn content is increased to replace Ni, then the cost decreases, but the mechanical properties cannot be secured
Solution Approach 1:
The patent employs a composite alloying system where Mn (4.1-30.0%) is combined with Cr (0-20.0%), Mo (0-10.0%), Nb (0-1.000%), Ti (0-0.100%), V (0-1.00%), and Al (0-0.100%) to create synergistic effects that maintain austenite phase stability, enhance strength, and secure mechanical properties while reducing Ni content
Solution Approach 2:
The patent applies local quality by assigning specific functions to different alloying elements: Mn for austenite stabilization, Cr and Mo for solid solution strengthening, Nb and Ti for precipitation hardening, V for grain refinement, and Al for deoxidation, allowing each element to contribute optimally to mechanical properties
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 weld metal achieves high toughness at low temperatures while being cost-effective, with a balanced composition that prevents stacking fault energy loss and mechanical property deterioration.
Implementation Method 1
Mn has a similar effect (to Ni in stabilizing austenite phase). Therefore, when the Ni content is reduced and the Mn content is increased, a weld metal that is inexpensive and has high toughness in low-temperature is obtained
Data Source
AI summary
A weld metal including C: 0.030% to 1.000%, Si: from 0.03% to 0.50%, Mn: 4.1% to 30.0%, P: 0% to 0.050%, S: 0% to 0.050%, Cu: 0% to 5.0%, Ni: 1.0% to 30.0%, Cr: 0% to 20.0%, Mo: 0% to 10.0%, Nb: 0% to 1.000%, V: 0% to 1.00%, Co: 0% to 1.00%, Pb: 0% to 1.00%, Sn: 0% to 1.00%, W: 0% to 20.0%, Mg: 0% to 5.0%, Al: 0% to 0.100%, Ca: 0% to 5.0%, Ti: 0% to 0.100%, B: 0% to 0.5000%, REM: 0% to 0.500%, Zr: 0% to 0.500%, N: 0% to 0.5000%, O: 0.0010% to 0.1500%, and balance: Fe and impurities, wherein, Mn+Ni: 5.0% or more, and Nb+Ti+V+Al: 0.005% or more.