690 MPa Bridge Steel Rust Stabilization Liquid for No-Flow Coverage

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Solution Overview

Problem

Existing technologies fail to stabilize the rust layer on 690 MPa-grade weather-resistant bridge steel members, leading to non-uniform rust layer color and rusty liquid flow, which affects aesthetic consistency and environmental pollution.

Innovation Solution

A stabilization treatment liquid comprising ferric chloride, sodium bisulfite, chromium sulfate, potassium permanganate, polypropylene glycol, and sodium carboxymethyl cellulose is applied to form a uniform brown rust layer by promoting chemical and electrochemical reactions, with the humectant maintaining moisture and thickener increasing residence time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If rust layer stabilization treatment is applied to 690 MPa-grade weather-resistant bridge steel members, then the rust layer can be stabilized, but the treatment liquid flows over various parts of the member causing non-uniform color and liquid flow

Engineering Contradiction:
Improverust layer stabilityVSAvoidsurface color uniformity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent changes the physical parameters of the treatment liquid by adding a thickening agent to increase its viscosity. This modifies the liquid's flow characteristics, allowing it to remain stationary on vertical and inclined surfaces rather than flowing down, thereby achieving uniform coverage and consistent rust layer color across all surfaces of the steel member.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the treatment liquid is applied to all surfaces of large-sized steel members, then complete rust layer stabilization is achieved, but the liquid flows over various parts causing non-uniform color

Engineering Contradiction:
Improverust layer stabilization completenessVSAvoidsurface color consistency
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

By increasing the viscosity of the treatment liquid through the addition of a thickening agent, the liquid maintains its position on application surfaces without flowing to lower areas. This parameter change enables complete coverage of all surfaces including vertical and inclined ones, ensuring uniform rust layer formation and consistent color across the entire steel member.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If natural rust layer formation is allowed to proceed without treatment, then the steel member can be protected, but it takes 3 to 10 years for the rust layer to stabilize

Engineering Contradiction:
Improverust layer protectionVSAvoidstabilization time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies a stabilization treatment liquid containing corrosion inhibitors and rust layer stabilizers to the steel surface before natural rusting occurs. This preliminary chemical treatment prepares the surface and promotes rapid, uniform rust layer formation, reducing the stabilization time from 3-10 years to a much shorter period while maintaining protective functionality.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The treatment liquid contains strong oxidizing agents that accelerate the oxidation process. Instead of allowing slow natural rusting over several years, the oxidants rapidly convert the steel surface to a stable rust layer, significantly reducing the time required for stabilization while maintaining the protective function.

Inventive Principle:
Principle #38Strong oxidants (Accelerated oxidation)

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 treatment forms a stable, uniformly colored rust layer with no liquid flow, achieving a thickness of ≥80 μm, color difference ≤10, and rust layer amount ≥25 g/m2 on the steel member surface.

Implementation Method 1

promoting chemical and electrochemical reactions

Methodology Applied
Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 2

promoting chemical and electrochemical reactions

Methodology Applied
Scientific EffectElectrochemical reaction: Electrochemiluminescence

Implementation Method 3

the humectant maintaining moisture

Methodology Applied
Scientific EffectHumectant action: Absorption (physical)

Implementation Method 4

thickener increasing residence time

Methodology Applied
Scientific EffectThickening: Viscometer

Data Source

PatentUS20250305151A1Stabilization treatment liquid for 690 mpa-grade weather-resistant bridge steel member, treatment method and use
Publication Date: 2025.10.02 BAOSHAN IRON & STEEL CO LTD

AI summary

Disclosed is a stabilization treatment liquid for a 690 MPa-grade weather-resistant bridge steel member. The content in percentage by mass of each component of the stabilization treatment liquid is as follows: the content of ferric trichloride is 3-7%; the content of sodium bisulfite is 1-2%; the content of chromium sulfate is 3-6%; the content of potassium permanganate is 1-4%; the content of polypropylene glycol is 1-2%; the content of sodium carboxymethyl cellulose is 2-5%; and the remainder is deionized water. Also provided is a method for performing stabilization treatment by using the stabilization treatment liquid. According to the present invention, stabilization treatment for a rust layer of a 690 MPa-grade weather-resistant bridge steel member can be achieved, and after treatment, a brown rust layer having uniform color and no rust liquid flow is formed on the surface of the 690 MPa-grade weather-resistant bridge steel member.