Chemical Lead Grade refers to high-purity lead and carefully controlled low-alloy lead grades designed specifically for chemical processing applications. In these environments, corrosion resistance, chemical stability, impermeability, and long service life are far more critical than mechanical strength.
These grades are widely used in acid plants, fertilizer units, chemical reactors, and containment systems where aggressive chemicals are present.
Material Basis
Chemical Lead Grades are commonly based on:
✔ Pure Lead (UNS L50000–L50099)
✔ Low-alloy Lead (silver-bearing or calcium-bearing, tightly controlled)
Microstructure & Metallurgical Behavior
| Feature | Description |
|---|---|
| Crystal Structure | Face-Centered Cubic (FCC) |
| Microstructure | Coarse equiaxed grains |
| Strengthening | Essentially none (pure metal) |
| Optional Alloying | Silver improves creep resistance |
| Recrystallization | Occurs near room temperature |
| Work Hardening | Minimal |
Metallurgical Insight:
Chemical lead remains soft throughout service life, allowing it to absorb thermal
expansion and vibration without cracking.
Corrosion & Chemical Resistance
Excellent Resistance To:
✔ Sulfuric acid (all concentrations – key advantage)
✔ Phosphoric acid
✔ Dilute hydrochloric acid
✔ Fertilizer chemicals
✔ Industrial atmospheres
✔ Soil corrosion
Limited / Poor Resistance To:
❌ Nitric acid
❌ Strong oxidizing agents
❌ High-velocity corrosive flows
Chemical lead forms stable, adherent oxide or sulfate films that protect the base metal from further attack.
Fabrication, Processing & Refining
| Process | Performance |
|---|---|
| Rolling / Sheet Forming | Excellent |
| Press Forming & Bending | Excellent |
| Lead Burning (Gas Welding) | Excellent |
| Soldering | Excellent |
| Machining | Rarely required (smears) |
Refining is carried out using pyrometallurgical methods or electrolytic refining for high-purity chemical grades. Controlled silver additions may be introduced when improved creep resistance is required.
Available Forms
Lead sheets & plates
Pipes & tubes
Lead wool
Ingots
Bricks & blocks
Custom linings & fabricated vessels
Key Characteristics
✔ Outstanding resistance to industrial acids
✔ Soft, flexible, and crack-resistant
✔ Impermeable to liquids and gases
✔ High density
✔ Excellent vibration absorption
✔ Long service life in static chemical environments
Applications
Chemical & Fertilizer Plants
Sulfuric acid chambers, acid storage tanks, pickling tank linings,
reactors, scrubbers
Power & Metallurgy
Acid handling systems, electrolytic cells
Construction & Infrastructure
Chemical containment linings, acid-proof flooring systems
Environmental & Nuclear
Radiation shielding, chemical containment barriers
Advantages of Chemical Lead Grade
✔ Unmatched sulfuric acid resistance
✔ Self-healing protective oxide layers
✔ Easy on-site fabrication and repair
✔ Long service life with minimal maintenance
✔ Highly recyclable material
Why Choose Chemical Lead Grade?
Choose Chemical Lead Grade when chemical resistance is critical, sulfuric or phosphoric acid is present, structural strength is not the primary requirement, and proven long-term corrosion performance is essential.
Engineering Summary:
Chemical Lead Grade is a special-purpose material selected not for strength, but
for extraordinary chemical durability, impermeability, and reliability in harsh
industrial environments.