Tin Blackplate Composition for Welded Container Formability

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Solution Overview

Problem

Existing tin blackplates used for manufacturing containers face issues with welded part bursts due to inadequate weldability and workability, particularly during secondary processing like expansion, and are prone to defects such as fluting and stretcher strain due to deformation aging, especially when produced by continuous annealing methods.

Innovation Solution

A tin blackplate composition optimized with specific alloying elements like boron, titanium, and chromium, controlled through precise atomic ratios, combined with a manufacturing process involving slab production, hot-rolling, cold-rolling, and annealing, to enhance weldability and workability, ensuring a uniform welding heat affected zone and reduced particle diameter differences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If continuous annealing method is used to improve productivity, then productivity is improved, but deformation aging occurs causing fluting and stretcher strain defects

Engineering Contradiction:
ImproveproductivityVSAvoiddefect rate
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies parameter changes by precisely controlling the composition ranges of alloying elements (Ti: 0.01-0.035%, B: 0.0005-0.003%, Al: 0.01-0.06%, N: 0.0005-0.004%) and maintaining specific atomic ratio relationships ([Ti]+[Al])/[N]-[B] between 4.8-12.5 and ([Ti]-[N])/[C] between 0.8-2.5). This compositional parameter optimization prevents deformation aging during continuous annealing while maintaining high productivity, resolving the contradiction between production efficiency and defect prevention.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system by combining multiple alloying elements (Ti, B, Al, N, C) in specific proportions to achieve synergistic effects. Titanium and boron form fine precipitates that suppress aging, while aluminum provides solid solution strengthening. This composite approach allows continuous annealing to be performed without fluting or stretcher strain, resolving the contradiction between productivity improvement and defect reduction.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If welding is performed to join container parts, then joinability is improved, but welded part bursts occur during secondary processing

Engineering Contradiction:
ImprovejoinabilityVSAvoidwelded part strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent changes material parameters by optimizing carbon content to 0.0005-0.005% (ultra-low carbon) and controlling the atomic ratios of alloying elements. This parameter optimization ensures that the welding heat affected zone develops a fine microstructure without excessive grain growth, preventing bursts during expansion while maintaining good weldability through appropriate compositional balance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by creating a fine-grained microstructure specifically in the welding heat affected zone through controlled alloying. The titanium and boron elements promote fine precipitate formation locally during welding, while the overall compositional control ensures uniform fine structure throughout the material, preventing localized weakness that would cause bursts during secondary processing.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If ultra-low carbon steel is used to improve weldability, then weldability is improved, but workability deteriorates due to aging phenomenon

Engineering Contradiction:
ImproveweldabilityVSAvoidworkability
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

The patent introduces titanium and boron as intermediary elements that form fine precipitates to suppress aging. These intermediaries prevent the degradation of workability that would normally occur in ultra-low carbon steels by blocking dislocation movement and preventing grain boundary sliding during deformation, while maintaining the low carbon content needed for good weldability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite material system where ultra-low carbon steel is combined with specific amounts of titanium, boron, and aluminum. This composite structure provides both the weldability of low-carbon steel and the aging resistance needed for good workability, resolving the contradiction between ease of manufacture and ease of operation through synergistic element combinations.

Inventive Principle:
Principle #40Composite materials

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 solution provides improved weldability and workability, preventing welded part bursts and reducing defects like fluting and stretcher strain, while enhancing productivity and expanding application to food and drink pipes, pressure-resistant pipes, and pail cans.

Implementation Method 1

the control of solid solution elements in steel

Methodology Applied
Scientific EffectSolid solution strengthening: Solid Solution Strengthening

Implementation Method 2

a manufacturing process involving slab production, hot-rolling, cold-rolling, and annealing

Methodology Applied
Scientific EffectAnnealing: Annealing

Data Source

PatentUS12595537B2Tin blackplate for processing and method for manufacturing same
Publication Date: 2026.04.07 POHANG IRON & STEEL CO LTD

AI summary

The present invention provides a tin blackplate for processing and a method for manufacturing the same.The tin blackplate according to an exemplary embodiment of the present invention comprises: in % by weight, 0.0005 to 0.005% of carbon (C), 0.15 to 0.60% of manganese (Mn), 0.01 to 0.06% of aluminum (Al), 0.0005 to 0.004% of nitrogen (N), 0.0005 to 0.003% of boron (B), 0.01 to 0.035% of titanium (Ti), and the balance being iron (Fe) and inevitable impurities, and satisfies the following Formula 1.4.8≤([Ti]+[Al])/[N]−[B]≤12.5  [Equation 1]In this case, in Equation 1, [Ti], [Al], [N], and [B] mean each value obtained by dividing the content (% by weight) of Ti, Al, N, and B in the blackplate by each atomic weight thereof.