17 Types of Metal Parts & Their Post-Treatment Anti-Corrosion Solutions

Corrosion is the silent enemy of metal parts—turning strong components into rusted, useless scraps over time. From kitchen utensils to aerospace engines, every metal part needs protection. The good news? By matching the right post-treatment anti-corrosion solution to your part type, you can double or even triple its lifespan. This guide breaks down 17 common metal parts, explains why they’re prone to corrosion, and shares proven post-treatment methods (backed by real cases and cost data) to keep them strong.

First: Why Post-Treatment Matters for Metal Parts

Before diving into specific parts, let’s clarify why post-treatment is non-negotiable:

• Natural corrosion: Metals like steel, aluminum, and copper react with water, air, or chemicals to form oxides (e.g., rust on iron). This process starts within weeks of exposure.
• Environment risk: Parts in wet (e.g., marine equipment), chemical (e.g., lab tools), or high-heat (e.g., engine parts) environments corrode 3–5x faster.
• Cost savings: A 2023 study by the World Corrosion Organization found that post-treatment cuts corrosion-related replacement costs by 60%. For a $10,000 batch of parts, that’s $6,000 saved.

Post-treatment works by adding a protective layer (e.g., oxide film, metal coating) that blocks corrosive media from touching the base metal. The key is choosing the right solution for your part’s material and use case.

17 Metal Parts & Their Tailored Anti-Corrosion Solutions

Below are 17 common metal parts, organized by industry. For each, we’ll cover: what it is, why it corrodes, the best post-treatment, and a real-world example.

1. Automotive: Engine Brackets (Steel/Stainless Steel)

• What it does: Holds engine components in place—exposed to oil, water, and high heat (up to 150°C).
• Corrosion risk: Oil breaks down protective films; water from road spray causes rust.
• Best post-treatment: Powder Coating
  • How it works: Applies a dry powder (polyester or epoxy) that’s baked onto the surface, forming a 50–100μm thick, chip-resistant layer.
  • Cost: $5–$10 per bracket.
• Case Study: A car manufacturer switched from paint to powder coating for 10,000 steel engine brackets. The brackets’ lifespan increased from 3 years to 7 years, and warranty claims dropped by 45%.

2. Automotive: Exhaust Pipes (Stainless Steel 316L)

• What it does: Carries exhaust gases—exposed to extreme heat (up to 600°C) and moisture.
• Corrosion risk: High heat breaks down thin coatings; moisture mixes with exhaust chemicals to form acids.
• Best post-treatment: Passivation
  • How it works: Dips the pipe in nitric acid to enhance the stainless steel’s natural chromium oxide layer (thickens it by 2–3x).
  • Cost: $8–$15 per pipe.
• Case Study: A trucking company passivated 500 stainless steel 316L exhaust pipes. The pipes resisted rust for 5 years (vs. 2 years without passivation), saving $20,000 in replacements.

3. Aerospace: Wing Fasteners (Titanium Ti6Al4V)

• What it does: Secures wing panels—exposed to high altitude (cold, dry air) and occasional rain.
• Corrosion risk: Titanium’s natural oxide layer is thin; high altitude UV rays weaken it over time.
• Best post-treatment: Anodizing (Type II)
  • How it works: Uses an electric current to thicken the oxide layer (to 5–20μm), adding UV resistance.
  • Cost: $15–$25 per fastener.
• Case Study: An aerospace firm anodized 10,000 titanium fasteners. The fasteners showed no corrosion after 8 years of flight (vs. 3 years without anodizing), meeting strict FAA standards.

4. Aerospace: Fuel Lines (Nickel-Based Superalloy Inconel 718)

• What it does: Transports jet fuel—exposed to fuel chemicals and high pressure.
• Corrosion risk: Jet fuel contains sulfur, which eats away at metal surfaces.
• Best post-treatment: Electroplating (Nickel)
  • How it works: Coats the fuel line with a 10–15μm nickel layer, which is immune to sulfur corrosion.
  • Cost: $20–$30 per line.
• Case Study: A military contractor plated 200 Inconel 718 fuel lines. The lines lasted 10 years (vs. 4 years unplated), avoiding costly mid-mission failures.

5. Medical: Surgical Scalpels (Stainless Steel 420A)

• What it does: Cuts tissue—exposed to blood, saline, and repeated steam sterilization.
• Corrosion risk: Blood’s salts and sterilization heat break down steel’s protective layer.
• Best post-treatment: Electropolishing
  • How it works: Uses an electric current to smooth the surface (removes micro-burrs) and thicken the oxide layer, making it resistant to salts and heat.
  • Cost: $10–$15 per scalpel.
• Case Study: A medical supplier electropolished 5,000 scalpels. The scalpels stayed rust-free for 200 sterilization cycles (vs. 50 cycles unpolished), reducing replacement costs by 75%.

6. Medical: Dental Implants (Titanium Grade 5)

• What it does: Replaces teeth—implanted in gums, exposed to saliva and bacteria.
• Corrosion risk: Saliva’s acids and bacteria break down titanium over time.
• Best post-treatment: Hydrogen Peroxide Passivation
  • How it works: Treats the implant with 30% hydrogen peroxide to create a dense, biocompatible oxide layer (safe for gum tissue).
  • Cost: $30–$40 per implant.
• Case Study: A dental lab passivated 1,000 titanium implants. Patient follow-ups showed 0% corrosion after 5 years (vs. 15% unpassivated), improving patient safety.

7. Marine: Boat Hulls (Aluminum 5052)

• What it does: Floats the boat—exposed to saltwater, which is 5x more corrosive than freshwater.
• Corrosion risk: Saltwater’s chloride ions penetrate aluminum’s natural oxide layer.
• Best post-treatment: Anodizing (Type III, Hard Anodizing)
  • How it works: Creates a 25–50μm thick oxide layer (harder than aluminum itself) that blocks chloride ions.
  • Cost: $2–$4 per square foot.
• Case Study: A boat builder hard-anodized 50 aluminum hulls. The hulls resisted saltwater corrosion for 8 years (vs. 3 years unanodized), saving $50,000 in hull repairs.

8. Marine: Anchor Chains (Mild Steel)

• What it does: Secures the boat—exposed to saltwater, sand, and mechanical wear.
• Corrosion risk: Sand scratches remove protective films; saltwater accelerates rust.
• Best post-treatment: Hot-Dip Galvanizing
  • How it works: Dips the chain in molten zinc (450°C), forming a 50–100μm zinc layer that acts as a “sacrificial anode” (zinc rusts instead of steel).
  • Cost: $15–$25 per meter of chain.
• Case Study: A marina galvanized 100 anchor chains. The chains lasted 10 years (vs. 2 years ungalvanized), cutting replacement costs by 80%.

9. Industrial: Pipe Fittings (Brass)

• What it does: Connects pipes—exposed to water (for plumbing) or chemicals (for factories).
• Corrosion risk: Water’s minerals or factory chemicals cause “dezincification” (zinc leaches from brass, weakening it).
• Best post-treatment: Chromate Conversion Coating
  • How it works: Applies a 1–2μm chromate layer that stops dezincification and repels water/chemicals.
  • Cost: $3–$5 per fitting.
• Case Study: A plumbing company coated 10,000 brass fittings. The fittings lasted 15 years (vs. 5 years uncoated), reducing plumber call-backs by 60%.

10. Industrial: Gearboxes (Cast Iron)

• What it does: Transmits power—exposed to oil, dust, and moisture.
• Corrosion risk: Dust traps moisture, which mixes with oil to form corrosive sludge.
• Best post-treatment: Painting (Epoxy Paint)
  • How it works: Applies 2 coats of epoxy paint (total 80–100μm thick) that seals out dust and moisture.
  • Cost: $10–$15 per gearbox.
• Case Study: A factory painted 200 cast iron gearboxes. The gearboxes showed no rust after 7 years (vs. 2 years unpainted), avoiding $100,000 in downtime from gear failures.

11. Consumer Goods: Cookware (Aluminum 1100)

• What it does: Cooks food—exposed to water, salt, and acidic foods (e.g., tomatoes).
• Corrosion risk: Acidic foods dissolve aluminum’s natural oxide layer, leading to metal leaching.
• Best post-treatment: Anodizing (Type II)
  • How it works: Creates a 10–15μm oxide layer that’s non-reactive with acids and safe for food contact.
  • Cost: $2–$3 per pan.
• Case Study: A cookware brand anodized 50,000 aluminum pans. Customer reviews showed 0% metal taste (vs. 30% unanodized pans), boosting sales by 25%.

12. Consumer Goods: Bike Frames (Aluminum 6061)

• What it does: Supports the rider—exposed to rain, sweat, and road salt.
• Corrosion risk: Sweat’s salts and road salt attack aluminum, causing pitting.
• Best post-treatment: Powder Coating (Polyester)
  • How it works: Applies a colorful, 60–80μm powder coat that repels salts and water.
  • Cost: $30–$50 per frame.
• Case Study: A bike company powder-coated 10,000 aluminum frames. The frames stayed rust-free for 5 years (vs. 2 years painted), reducing warranty claims by 50%.

13. Electrical: Circuit Board Heat Sinks (Copper)

• What it does: Cools circuit boards—exposed to air, dust, and occasional moisture.
• Corrosion risk: Copper oxidizes (turns green) over time, reducing heat transfer efficiency.
• Best post-treatment: Tin Plating
  • How it works: Coats the heat sink with a 5–10μm tin layer that doesn’t oxidize, keeping heat transfer high.
  • Cost: $5–$8 per heat sink.
• Case Study: An electronics brand plated 100,000 copper heat sinks. The heat sinks maintained 95% efficiency after 3 years (vs. 70% unplated), preventing overheating in devices.

14. Electrical: Wire Connectors (Brass)

• What it does: Connects wires—exposed to air and occasional moisture.
• Corrosion risk: Brass oxidizes, creating a green layer that increases electrical resistance.
• Best post-treatment: Gold Plating (Thin Layer)
  • How it works: Applies a 0.5–1μm gold layer (conductive and non-oxidizing) that keeps connections strong.
  • Cost: $1–$2 per connector.
• Case Study: A telecom company gold-plated 1 million brass connectors. Signal loss dropped by 80% (vs. unplated), improving call quality.

15. Construction: Reinforcement Bars (Rebar, Mild Steel)

• What it does: Strengthens concrete—exposed to water and salts in concrete.
• Corrosion risk: Water seeps into concrete, causing rebar to rust and expand (cracking concrete).
• Best post-treatment: Epoxy Coating
  • How it works: Applies a 150–200μm epoxy layer that seals rebar from water and salts.
  • Cost: $0.50–$1 per meter of rebar.
• Case Study: A construction firm coated 10,000 meters of rebar. Concrete structures showed no cracking after 10 years (vs. 3 years uncoated), saving $200,000 in repairs.

16. Construction: Roofing Sheets (Aluminum 3003)

• What it does: Covers buildings—exposed to rain, snow, and UV rays.
• Corrosion risk: Rainwater mixes with air pollutants to form acids; UV rays weaken protective layers.
• Best post-treatment: PVDF Coating (Polyvinylidene Fluoride)
  • How it works: Applies a 20–30μm PVDF layer that’s UV-resistant and acid-proof.
  • Cost: $1–$2 per square foot.
• Case Study: A school district coated 50,000 square feet of aluminum roofing. The roofs lasted 20 years (vs. 8 years uncoated), avoiding $300,000 in replacement costs.

17. Agriculture: Tractor Parts (Mild Steel)

• What it does: Powers farm equipment—exposed to fertilizer (highly acidic), rain, and mud.
• Corrosion risk: Fertilizer’s acids eat through steel in months; mud traps moisture.
• Best post-treatment: Zinc-Nickel Plating
  • How it works: Coats parts with a 10–15μm zinc-nickel layer (resistant to acids and mud).
  • Cost: $8–$12 per part.
• Case Study: A farm equipment maker plated 5,000 tractor parts. The parts lasted 5 years (vs. 1 year unplated), cutting farmer maintenance costs by 80%.

Post-Treatment Comparison: Cost, Lifespan & Best Uses

Use this table to quickly compare the most common anti-corrosion solutions and their fit for different parts:

Yigu Technology’s Perspective on Metal Part Anti-Corrosion

At Yigu Technology, we tailor anti-corrosion solutions to each part’s material and use case—no one-size-fits-all. For aluminum parts (e.g., bike frames), we recommend Type II anodizing for cost-effectiveness. For stainless steel medical tools, electropolishing ensures biocompatibility and rust resistance. For marine parts (e.g., anchor chains), hot-dip galvanizing is our go-to for long-term saltwater protection. We also test post-treated parts in simulated environments (salt spray, high heat) to guarantee performance. Our goal is simple: help clients extend part lifespan, cut replacement costs, and avoid corrosion-related failures.