Anchor Chain Steel Composition for Corrosion Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Anchor chains for ships suffer from short durable lifetime and inadequate corrosion resistance due to severe corrosion in seawater environments, necessitating improved steel materials with enhanced corrosion resistance.
Innovation Solution
A steel composition for anchor chains with specific chemical elements (C, Si, Mn, P, S, Al, N, Sn, Cr, Cu, Ni, Sb, Mo, W, V, Ca, Mg, REM, Nb, Ti, and B) is developed, with controlled content ranges to optimize corrosion and wear resistance, and a corrosion test method simulating the anchor chain's environment to evaluate and enhance corrosion resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional steel materials (SBC300, SBC490, SBC690) are used for anchor chains, then the anchor chain can be manufactured with adequate strength, but the corrosion resistance is insufficient and the durable lifetime is short
Solution Approach 1:
The patent applies parameter changes by precisely controlling the chemical composition parameters of the steel material. Specific ranges are defined for C (0.15-0.45%), Si (0.01-0.60%), Mn (1.00-2.50%), P (≤0.050%), S (≤0.050%), Al (0.005-0.100%), Sn (0.010-0.500%), Cr (0.010-0.100%), Cu (0.001-0.100%), Ni (0.010-5.00%), and other elements. This precise parameter control transforms the steel's corrosion resistance while maintaining manufacturability and strength.
Solution Approach 2:
The patent creates a composite material system by combining multiple alloying elements in specific proportions. The steel contains Fe as base metal with controlled additions of C, Si, Mn, P, S, Al, Sn, Cr, Cu, Ni, and optional elements (Sb, Mo, W, V, Ca, Mg, REM, Nb, Ti, B). This composite composition synergistically improves corrosion resistance, strength, and wear resistance beyond what single-element additions could achieve.
2Reliability
If alloying elements are added to improve corrosion resistance, then the corrosion resistance increases, but the manufacturing complexity and cost increase
Solution Approach 1:
The patent manages complexity by establishing clear parameter boundaries for each alloying element. Instead of unlimited additions, specific ranges are set (e.g., Sn: 0.010-0.500%, Cr: 0.010-0.100%, Ni: 0.010-5.00%). This transforms the composition control from an open-ended complex problem to a managed parameter optimization problem with defined limits.
Solution Approach 2:
The patent applies local quality by assigning specific functional roles to different alloying elements at specific concentration ranges. For example, Sn (0.010-0.500%) specifically enhances corrosion resistance in seawater, while Cr (0.010-0.100%) and Ni (0.010-5.00%) contribute to both corrosion and oxidation resistance. This localized functional assignment optimizes each element's contribution while controlling overall complexity.
Data Source
AI summary
This invention provides a steel for an anchor chain having a chemical composition consisting of, in mass%, C: 0.15 to 0.45%, Si: 0.6% or less, Mn: 1.00 to 2.50%, P: 0.1% or less, S: 0.05% or less, Al: 0.1% or less, N: 0.01% or less, Sn: 0.01 to 0.5%, Cr: 0.1% or less, Cu: 0.1% or less, Ni: 0 to 5.0%, Sb: 0 to 0.5%, Mo: 0 to 1.0%, W: 0 to 1.0%, V: 0 to 1.0%, Ca: 0 to 0.01%, Mg: 0 to 0.01%, REM: 0 to 0.01%, Nb: 0 to 0.1%, Ti: 0 to 0.1%, B: 0 to 0.01%, and the balance: Fe and impurities, and satisfying the formulas [1-3.26Sn+0.25Cr ≤ 0.80] and [Sn/Cu ≥ 1.0], and also provides an anchor chain that uses the steel for an anchor chain.