CORE SERVICE OFFERINGS
TCR Engineering Services undertakes a wide range of corrosion and stress corrosion tests as per ASTM, NACE or those that are specific to an individual client’s requirements. Senior technicians are available to provide consulting and advisory services on corrosion prevention and control services including material selection either in the laboratory or on-site inspection.
TCR’s technical team has developed deep industry expertise to address a variety of corrosion problems that an organization encounters like in the field of oil and gas production & transmission, energy conversion systems and nuclear power systems. A wide variety of corrosion-related tests are undertaken to determine weight loss corrosion, intergranular attack, pitting corrosion, corrosion fatigue, stress corrosion cracking, sulfide stress cracking, and hydrogen-induced cracking.
TCR offers a comprehensive range of material testing services for corrosion problems that include:
Inter-granular Corrosion attack in Austenitic Stainless Steels
Oxalic Acid Etch test per ASTM A262 Practice A
Ferric Sulfate-Sulfuric Acid test per ASTM A262 Practice B
Huey Test, Nitric Acid test per ASTM A262 Practice C
Copper–Copper Sulfate–Sulfuric Acid test per ASTM A262 Practice E
Copper–Copper Sulfate–50% Sulfuric Acid test per ASTM A262 Practice F
Inter-granular Corrosion attack in Stainless Steels
Oxalic acid etch test per ASTM A763 method W
Ferric sulfate-sulfuric acid test per ASTM A763 method X
Copper-copper sulfate-50% sulfuric acid test per ASTM A763 method Y
Copper-copper sulfate-16% sulfuric acid test per ASTM A763 method Z
Inter-granular Corrosion of Ferritic, Austenitic & Ferritic-Austenitic (Duplex) Stainless Steel
Intergranular corrosion of stainless steels per ISO 3651 Method A, B, C
Potentiodynamic Anodic Polarization Measurement per ASTM G5
Immersion Corrosion Testing per ASTM G31
Stress Corrosion Cracking in Polythionic Acids per ASTM G35
Preparing, Cleaning and Evaluating Corrosion Test Specimens per ASTM G1
Examination and Evaluation of Pitting Corrosion per ASTM G46
Corrosion Rates and Related Information from Electrochemical Measurements (Tafel slopes) per ASTM G102
Corrosion Tests as per ONGC/EIL specification
Chloride Stress Corrosion Cracking in boiling Magnesium Chloride per ASTM G36
Chloride Stress Corrosion Cracking in boiling Calcium Chloride per ASTM G36
Determining Susceptibility to Stress-Corrosion Cracking of Aluminium Alloy Products
Stress Corrosion Cracking by Alternate Immersion Method per ASTM G44
Stress Corrosion Cracking of Aluminum Alloys per ASTM G47 Stress Corrosion Cracking Resistance of Al-Zn-Mg-Cu Alloys per ASTM G103
Exfoliation Corrosion Susceptibility of Aluminum Alloys (ASSET Test) per ASTM G66
Exfoliation Corrosion Susceptibility in Aluminium Alloys (EXCO Test) per ASTM G34
Intergranular Corrosion of Aluminum Alloys by Mass Loss (NAMLT Test) per ASTM G67
Intergranular Corrosion Resistance of Heat Treatable Aluminium Alloys per ASTM G110
Pitting and Crevice Corrosion Resistance of Stainless Steels and Related Alloys
Ferric Chloride pitting test G48 method A
Ferric Chloride crevice test ASTM G48 method B
Critical Pitting Temperature test for nickel-base and chromium-bearing alloys per ASTM G48 method C
Critical Crevice Temperature test for nickel-base and chromium-bearing alloys per ASTM G48 method D
Critical Pitting Temperature test for Stainless Steel ASTM G48 method E
Critical Crevice Temperature test for Stainless Steel ASTM G48 method F
Detecting Detrimental Intermetallic Phase in Austenitic/Ferritic (Duplex) Stainless Steel
Sodium Hydroxide Etch test of Duplex Stainless Steel per ASTM A923 method A
Charpy Impact test for Classification of Structures of Duplex Stainless Steels per ASTM A923 method B
Ferric Chloride Corrosion test for Classification of Structures of Duplex Stainless Steels per ASTM A923 method C
NACE MR0175/ISO 15156: Petroleum and Natural Gas Industries- Materials for use in H2S-containing Environments in Oil and Gas production
Hydrogen Induced Cracking Test per NACE TM0284
Stress Oriented Hydrogen Induced Cracking Test (SOHIC) per NACE TM0103
Sulfide Stress Corrosion Cracking (Room Temperature) per NACE TM0177
Sulfide Stress Corrosion Cracking (90 Deg C, 16 bar) per NACE TM0177
Sulfide Stress Corrosion Cracking (120 Deg C, 20 bar) per NACE TM0177
Sulfide Stress Corrosion Cracking Double-Cantilever-Beam (DCB) Test per NACE TM0177 method D
Stress Corrosion Cracking (Four-Point Bend) of Materials for Oil and Gas Applications per NACE TM0316
Stress Corrosion Cracking (Four-Point Bend) per NACE TM0177 and ASTM G39
Determining Susceptibility to Stress Corrosion Cracking in Copper Alloys
Stress Corrosion Cracking (Ammonia Vapor Test) per ASTM B858
Detection of Cuprous Oxide (Hydrogen Embrittlement Susceptibility) in Copper per ASTM B577
Metallic Material and Coated Metallic Subtrate
Salt Spray (Fog) per ASTM B117
Neutral salt spray (NSS) per ISO 9227
Acetic acid salt spray (AASS) per ISO 9227
Copper-accelerated acetic acid salt spray (CASS) per ISO 9227
TCR Core Services
SOUR GAS CORROSION
TCR’s Sour Service Corrosion Testing Department undertakes Small Scale Tests and Full Ring Testing for SSCC (NACE TM 0177, EFC 16 and 17) and HIC (NACE TM 0284). The range of instruments available to perform these tests is extensive and unrivalled in the industry. Highly experienced and qualified engineers routinely undertake corrosion studies to include all observations as per NACE MR 0175.
Hydrogen-Induced Cracking (HIC) Test
TCR Engineering Services’ corrosion testing laboratory performs HIC test to evaluate the resistance of pipelines, pressure vessel plate steels and hydrogen-induced Cracking caused by hydrogen absorption from aqueous sulfide corrosion. An unstressed test specimen is exposed to a solution at ambient temperature and pressure for a specified time, post which the test specimen is removed and evaluated.
NACE TM0284 specifies either Solution A or Solution B. Solution A is acidified brine. Solution B is simulated seawater prepared in accordance with ASTM D1141.52. In either case, H2S is bubbled through the solution constantly throughout the test period. NACE TM0284 specifies test duration of 96 hours.
PROCESS & OUTCOME
TCR Engineering issues a detailed written report on completion of each test. Each report includes a description of the test sample received, the test procedure used, and the pH values of the test solution, before exposure and after the exposure. The test bars are cut into sections and examined under a microscope for hydrogen-induced cracks. The dimensions of any such cracks are recorded and used to compute the values in percentage for Crack Length Ratio (CLR), Crack Thickness Ratio (CTR) and Crack Sensitivity Ratio (CSR).
To conduct the HIC test, the following sample sizes are required:
Plate - 150mm x150mm with rolling direction marked
If the plate is more than 80mm thick - 250mm x 250mm sample size is required
Pipe - upto 2" OD - 200mm long
If the pipe is more than 2" OD pipe - 100mm long sample size is required
Bars - Upto 3" dia - 300mm long
If the Bars are more than 3" dia to 5" dia - 200mm long sample size is required
If the Bars are more than 5" dia - 100mm long sample size is required
Number of pieces to be tested:
Up to 88mm thick/dia - Set of 3 pieces to be tested
More than 88mm thick/dia - 5 pieces to be tested
Sulfide Stress Corrosion Cracking (SSC)
PROCESS & OUTCOME
TCR Engineering provides a printed report for individual or cluster of tests conducted at the laboratory. The report includes a description of the test sample, details of the testing procedure and pH values of the test solution before and after exposure, along with the result of each test. TCR Engineering requires 6 weeks to complete the SSC test.
Sulfide stress corrosion cracking (SSC) is a form of hydrogen embrittlement cracking which occurs when a susceptible material is exposed to a corrosive environment containing water and H2S at a critical level of applied or residual tensile stress. TCR Engineering Services conducts the NACE TM0177 tests including Methods A and B for SSCC test at their corrosion testing laboratory.
NACE TM0177 tests at TCR includes both Tensile Test (Proof Rings) under Method A and Bent Beam Test (3 or 4 Point Bends) under Method B. NACE TM0177 specifies Solution A (acidified), Solution B (acidified and buffered) and Solution C (for martensitic stainless steel). Solution A is used in Methods A unless the properties of Solution B or C are specified. In any case, H2S is bubbled through the solution constantly throughout the test period.
Testing is performed in NACE solutions A and/or B, saturated with H2S at 24º and 90º Celsius. Stressed samples are exposed to sour environment for a predetermined time, after which they are removed and analyzed for crack detection. NACE TM0177 specifies test duration of 30 days (720 hours) for Method A or B test.
The SSC tests at TCR Engineering in India are performed routinely for customers, using tensile and bent beam specimens. For each stress level and temperature, the following sample size is required:
Plate- 16mm Thickness x 160mm long
Pipe- 160 long pieces irrespective of dia, cut strip of 16mm width
Bar- 160mm long piece irrespective of diameter
Several methodologies are available at TCR Engineering Services for testing intergranular corrosion. To conduct these tests, TCR carefully chooses a method that is suitable for steel grade and grain boundary composition. Intergranular corrosion in stainless steels may result from precipitation of carbides, nitrides or intermetallic phases.
Only in the most highly oxidizing solutions can an intergranular attack be caused by intermetallic phases. When a test is restricted to carbides in materials containing nitrides or intermetallic phases, a less oxidizing solution is chosen.
Services for testing Intergranular Corrosion
TCR Engineering Services frequently carries out a number of tests in India as per the ASTM A262 specification:
Oxalic Acid Test, ASTM A262, Practice A (Oxalic Acid Etch)
The oxalic acid etch test is a rapid method of screening specimens of certain stainless steel grades which are essentially free from susceptibility to intergranular attack associated with chromium carbide participates. The test is used for acceptance and not the rejection of a material.
Ferric Sulfate-Sulfuric Acid, ASTM A262 - Practice B (Streicher Test)
This test is based on weight loss determinations and provides a quantitative measure of relative performance of the material evaluated. The procedure includes subjecting a specimen to a 24 to 120-hour boil in ferric sulfate - 50% sulfuric acid. his procedure measures the susceptibility of stainless steel and nickel alloys to intergranular attack associated with the precipitation of chromium carbides at grain boundaries.aries.
Nitric Acid, ASTM A262, Practice C, (Huey Test)
The specimens are boiled for five periods, each for 48 hours in 65 percent nitric acid solution. The corrosion rate during each boiling period is calculated from the decrease in the weight of the specimens. The results, when properly interpreted can reveal whether or not the steel has been heat-treated in the correct manner. The customer must specify the maximum permissible corrosion rate and in applicable cases, provide the data on sensibilizing heat treatment.
The Huey test environment is strongly oxidizing and is only used as a check to ascertain if the material has been correctly heat treated. This test is suitable for the detection of chromium depleted regions as well as intermetallic precipitations, like sigma phase in the material. The Huey test is also used for materials that come into contact with strongly oxidizing agents, e.g. nitric acid. This procedure may also be used to check the effectiveness of stabilizing elements and of reductions in carbon content in reducing susceptibility to intergranular attack in chromium-nickel stainless steels.
Copper - Copper Sulfate - 16% Sulfuric acid, ASTM A262 - Practice E (Strauss Test)
This procedure is conducted to determine the susceptibility of austenitic stainless steel to intergranular attack associated with the precipitation of chromium-rich carbides. Once the specimen has been subjected to the solution boil, it is bent through 180° and over a diameter equal to the thickness of the specimen being bent. This test is based on a visual examination of the bent specimen.
Copper - Copper Sulfate - 50% Sulfuric acid, ASTM A262 - Practice F
This test is based on weight loss determination, which provides a quantitative measure of the relative performance of the material evaluated. It measures the susceptibility of "as received" stainless steel to intergranular attack.
The senior technical team at TCR Engineering Services has deep industry expertise in handling diverse corrosion problems encountered in oil and gas production, oil and gas transmission, energy conversion systems, and nuclear power systems. A wide variety of corrosion related tests can be undertaken at TCR Engineering Services to determine weight loss corrosion, intergranular corrosion attack, pitting corrosion, corrosion fatigue, stress corrosion cracking, sulfide stress corrosion cracking, and hydrogen-induced corrosion cracking. TCR also performs tests listed under 3rd party inspection of LRS, TUV, DNV, ABS and other inspection agencies at their laboratory.
Salt Spray (Neutral / Fog), ASTM B117
This is the most commonly used salt spray for testing inorganic and organic coatings, especially when such types of tests are used for material or product specifications. Salt Spray testing is a tool for evaluating the uniformity of thickness and the degree of porosity of metallic and nonmetallic protective coatings. A number of samples can be tested simultaneously depending on their size.
Pitting Corrosion Test, ASTM G48 Method B
This procedure is employed to assist in the selection of test methods that can be used in the identification and examination of pits as well as the evaluation of pitting corrosion to determine the extent of its effect. The ASTM G48 Method B, Ferric Chloride test involves exposing a specimen to a highly oxidizing acid chloride environment. The importance of this evaluation is to be able to determine the extent of pitting, either in a service application where it is necessary to predict the remaining life in a metal structure or in laboratory test programs that are used to select the most pitting-resistant materials for service.
Corrosion test as per ASTM G 35
The polythionic acid (sulfurous acid and hydrogen sulfide) environment provides a way of evaluating the resistance of stainless steels and related alloys to intergranular stress corrosion cracking. This practice can be applied to wrought products, castings, weld metal of stainless steel or other materials that are used in environments containing sulfur or sulfides.