Duplex Stainless Clad Steel Plate With Low-Precipitation Corrosion Control
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Solution Overview
Problem
Conventional duplex stainless clad steel plates exhibit insufficient corrosion resistance and mechanical properties, particularly in low-temperature environments, due to the precipitation of intermetallic compounds like sigma phase, carbides, and nitrides, which deteriorate the corrosion resistance of the cladding metal and require improved strength and toughness of the base metal.
Innovation Solution
The production method involves specific chemical compositions for the base and cladding metals, including controlled alloying elements like Cr, Mo, and Nb, along with precise thermal processing to prevent the precipitation of sigma phase and enhance the corrosion resistance and mechanical properties of the duplex stainless clad steel plate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional duplex stainless clad steel plates are used, then the base metal can provide strength and toughness, but the cladding metal exhibits insufficient corrosion resistance due to precipitation of intermetallic compounds
Solution Approach 1:
The invention changes the chemical composition parameters of the base metal by strictly controlling the content of alloying elements (Ti: 0.001-0.050%, Nb: 0.001-0.050%, V: 0.001-0.050%, Al: 0.001-0.050%, B: 0.0005-0.0050%, N: 0.001-0.010%) to prevent the formation of intermetallic compounds. This parameter optimization resolves the contradiction by eliminating the harmful precipitation while maintaining the required strength and toughness properties.
Solution Approach 2:
The invention creates an optimized composite structure where the base metal and cladding metal are metallurgically bonded. By carefully designing the base metal composition to be free of excessive intermetallic compounds and combining it with appropriate cladding metal, the composite achieves both the mechanical strength from the base metal and the corrosion resistance from the cladding metal without the harmful effects of intermetallic precipitation.
2Reliability
If the base metal composition is optimized to prevent intermetallic compound precipitation, then corrosion resistance improves, but manufacturing precision requirements increase
Solution Approach 1:
The invention establishes specific parameter ranges for alloying elements that balance corrosion resistance with manufacturing feasibility. By defining narrow but achievable ranges (e.g., Ti: 0.001-0.050%, Nb: 0.001-0.050%), the invention improves corrosion resistance while setting realistic manufacturing precision requirements that can be met with conventional steelmaking processes.
Data Source
Figure 1
AI summary
A duplex stainless clad steel plate excellent in the corrosion resistance of a cladding metal and the strength and toughness of a base metal is provided. Disclosed is a duplex stainless clad steel plate in which a duplex stainless steel plate as a cladding metal is bonded or joined to one or both surfaces of a base steel plate, in which the base steel plate comprises a predetermined chemical composition such that Nb/N is 3.0 or more and Ceq represented by the following Expression (1) is 0.35 to 0.45, and the duplex stainless steel plate comprises: a predetermined chemical composition such that PI defined by the following Expression (2) is 33.0 to 38.0; and a microstructure containing a ferrite phase in an area fraction of 35 % to 65 %, and in the microstructure, an amount of precipitated Cr is 1.00 % or less and an amount of precipitated Mo is 0.50 % or less: Ceq=C+Mn/6+Cu+Ni/15+Cr+Mo+V/5 and PI=Cr+3.3Mo+16N