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DC53 Steel Corrosion Resistance – A Detailed Guide

Do you wonder about the DC53 steel corrosion resistance? Many people choose DC53 steel for its high hardness, good toughness and long mold service life. You may worry: is DC53 steel stainless? Especially when using it in humid workshops or storing it under poor conditions. This article deeply analyzes the actual performance of DC53 Steel Corrosion Resistance.

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DC53 Steel vs D2

1. DC53 Chemical Composition and Its Influence

Chemical Composition：

  • C：1.00-1.10%

  • Si：≤0.40%

  • Mn：≤0.40%

  • P：≤0.030%

  • S：≤0.030%

  • Cr：8.0-9.0%

  • Mo：1.8-2.2%

  • V：0.2-0.5%

The Cr Content is only 8%, and this is the Key Point

Cr is the key element for steel corrosion resistance. Generally, Cr content over 12% forms a chromium oxide passivation film on the steel surface to prevent further corrosion, and such steel can be called stainless steel. DC53 has a Cr content of about 8.0%.

Mo Content Is About 2%, Helpful But Limited

Mo improves pitting resistance and boosts DC53 Steel Corrosion Resistance. However, Mo cannot fully work without enough Cr content. Therefore, Mo only makes a limited contribution to corrosion resistance.

C Content Is About 1% and Hurts Corrosion Resistance

C and Cr combine to form chromium carbide (Cr₂₃C₆). After chromium carbide precipitates, the Cr content in the surrounding area drops, and local corrosion resistance becomes weaker. This phenomenon is called the chromium-depleted zone.

2. Salt Spray Test

Salt Spray Test (ASTM B117) is a common method to measure DC53 Steel Corrosion Resistance.

  • Mild carbon steel (such as 45 steel): Red rust appears in 2-4 hours
  • Uncoated DC53: Pitting corrosion occurs in 12-24 hours
  • D2 (11-13% Cr): 24-48 hours
  • 304 stainless steel: 500-800 hours

If you place the mold in a dry workshop for normal use, DC53 steel has sufficient corrosion resistance. If the workshop is humid, contains acidic gas, or the mold is stored for a long time without oil coating, DC53 will rust.

3. Pitting Resistance Equivalent (PRE) Comparison

PRE = %Cr + 3.3×%Mo + 16×%N. The higher the value, the stronger the pitting resistance.

  • Mild carbon steel (e.g. 45 steel): Cr≈0%, Mo≈0%, N≈0% → PRE≈0
  • Uncoated DC53: Cr≈8%, Mo≈2%, N≈0% → PRE≈8 + 3.3×2 = 14.6
  • D2 (11-13% Cr): Cr≈12%, Mo≈1%, N≈0% → PRE≈12 + 3.3×1 = 15.3
  • 304 stainless steel: Cr≈18%, Mo≈0%, N≈0.1% → PRE≈18 + 16×0.1 = 19.6

4. Uniform Corrosion Rate Comparison (in 3.5% NaCl Solution)

The lower the uniform corrosion rate, the better the material resists general corrosion.
  • Mild carbon steel (e.g. 45 steel): Approximately 0.5 – 1.0 mm/year (rusts rapidly)
  • Uncoated DC53: Approximately 0.15 – 0.25 mm/year
  • D2 (11-13% Cr): Approximately 0.10 – 0.18 mm/year
  • 304 stainless steel: Approximately 0.001 – 0.01 mm/year (hardly rusts)

5. How to Avoid Corrosion Risks When Purchasing DC53

What is the Cr content?

It needs to be at least 8.5%. DC53 corrosion resistance is directly linked to Cr content.
 

Delivery condition:

Annealed grade rusts easily; pre-hardened grade is better. Polish and oil the surface after processing.
 

Coating service available?

Hard chrome plating or PVD coating can greatly improve DC53 corrosion resistance.

6. Conclusion

In Keyspark Steel, What we do:
  • Spot Supply → DC53 / Cr8Mo2SiV equivalent grades, round bars, flat bars and steel plates
  • Custom Supply → Non-standard sizes, customized heat treatment, large section forgives; delivery time 45–60 days
 

Each batch supplied with:

  • Original MTC with full chemical composition test data
  • Hardness test report
  • 100% ESR process with strict inclusion control
  • Ultrasonic inspection

📩 Contact us now if you need →

📧 Email: Sales@keysparksteel.com
📱 Mobile/WhatsApp: +86 150 2405 6480

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