Weight Loss Corrosion Testing: ASTM A262 & NACE RP0775

In the ever-evolving landscape of materials engineering, assessing corrosion resistance remains crucial for ensuring the long-term integrity of components exposed to harsh environments. At TCR Engineering’s state-of-the-art materials testing laboratory in Mahape, Navi Mumbai, India, we specialize in conducting weight loss corrosion tests — particularly ASTM A262 and NACE RP0775 — to evaluate the performance of metals under corrosive conditions. These tests are vital for industries such as oil & gas, petrochemicals, power generation, marine, and nuclear, where failure due to corrosion can lead to catastrophic outcomes.

What is Weight Loss Corrosion Testing?

Weight loss corrosion testing involves immersing a test specimen in a corrosive environment for a specific duration, after which it is cleaned and weighed to determine material loss. The test quantifies corrosion rates in mils per year (mpy) or millimeters per year (mm/y), giving a direct measure of the alloy’s resistance to corrosion in simulated service conditions.

This method is one of the oldest but most reliable and reproducible ways to compare material performance under real-world scenarios.

ASTM A262: Intergranular Corrosion in Stainless Steels

➤ Purpose:

ASTM A262 is the standard test practice for detecting susceptibility to intergranular attack (IGA) in austenitic stainless steels, especially those that have undergone improper heat treatment or welding.

➤ Commonly Tested Alloys:

• AISI 304, 316, 321, 347 series stainless steels

• Sensitized or stabilized grades

➤ Key Practices in ASTM A262:

There are five different practices (A through E), each simulating specific corrosive conditions to evaluate intergranular corrosion:

Practice	Description	Application
A	Oxalic Acid Etch Test	Rapid screening for sensitization
B	Streicher Test (HNO₃)	Nitric acid test for Cr-depleted grain boundaries
C	Huey Test	Five consecutive 48-hour boiling HNO₃ immersions
D	Copper–Copper Sulfate–16% Sulfuric Acid	Detects grain boundary attack
E	120-hour boiling in ferric sulfate–sulfuric acid	Severely aggressive test

➤ Output:

• Weight loss (mg/cm² or g/m²)

• Photographic evidence of etch attack (especially for Practice A)

• Pass/fail based on standard limits

TCR Engineering uses these tests to ensure that stainless steel components are not susceptible to intergranular corrosion, particularly before use in chemical and nuclear service.

NACE RP0775: Corrosion Testing in Sour Gas Environments

➤ Purpose:

NACE RP0775 (now updated and referenced under NACE/ASTM G193 terminology) provides a recommended practice for conducting corrosion tests in the presence of wet H₂S (hydrogen sulfide) environments — a typical condition in upstream oil and gas production.

➤ Why It Matters:

Hydrogen sulfide promotes sulfide stress cracking (SSC), hydrogen-induced cracking (HIC), and weight loss corrosion, especially in carbon steels and low alloy steels.

➤ Test Conditions:

• Exposure to acidic brines saturated with H₂S gas

• Controlled temperature and pressure environments (as per field simulation)

• Duration: From 24 hours to several weeks depending on client requirement

• Testing done under NACE TM0284, TM0177, or ISO 15156/NACE MR0175 complementary standards when needed
  

➤ Key Outputs:

• Corrosion rate (mm/y or mpy)

• Visual examination for blistering, pitting, and cracking

• Fractographic analysis for failure modes

• Weight change after cleaning per ASTM G1
  

TCR Engineering's team has extensive experience with corrosion testing protocols aligned with NACE RP0775, ensuring that materials meet safety and performance standards before field deployment.

Why Choose TCR Engineering for Weight Loss Corrosion Testing?

At TCR Engineering, we combine meticulous adherence to international standards with decades of expertise in metallurgy and failure analysis. Our laboratories are equipped with:

✅ Automated and precision analytical balances

✅ Dedicated corrosion cells and test chambers

✅ H₂S handling capabilities with strict safety protocols

✅ SEM/EDS for corrosion product analysis

✅ Skilled corrosion scientists and metallurgists

We serve clients across Saudi Arabia, UAE, India, Qatar, Nigeria, and beyond, particularly in sectors where material reliability directly affects safety and cost-efficiency.

Applications of Weight Loss Corrosion Testing

• Material qualification for sour service pipelines (as per NACE MR0175 / ISO 15156)

• Weld procedure and post-weld heat treatment validation

• Life assessment for in-service components

• Comparative testing for alloy selection

• R&D for corrosion inhibitor performance

Final Thoughts

In critical industries, the cost of corrosion is not just financial — it’s also environmental and human. TCR Engineering’s weight loss corrosion testing services under ASTM A262 and NACE RP0775 provide clients with the assurance they need to proceed confidently with material selection and deployment.

We don't just test materials — we validate their fitness for purpose.