Hydrogen Induced Cracking Test - HIC Test Hydrogen induced cracking testing apparatus ( HIC test ) to test and accurately determine the hydrogen induced cracking over exposed test specimens as per NACE standards requirements. HIC testing is recommended to evaluate the resistance of pipeline and pressure vessel plate steels to hydrogen induced cracking corrosion caused by hydrogen absorption from aqueous sulfide corrosion. Unstressed test specimens are exposed to a solution at temperature of 25deg cent with continuous H2S gas flow. The test specimens are finally removed and evaluated. Test specimens determine susceptibility of metals in H2S service. HIC testing apparatus meet requirements of ASTM / NACE Standard TM0284 and suitable to test material as per requirements of NACE MR0175. Hydrogen induced cracking test apparatus is rectangular provided with ready to use connections fittings. HIC test apparatus is supplied with essential spares for uninterrupted long term testing. HIC test specimens are machined with thickness of 5-30mm, width 20mm, and length of 100mm is suitable for testing as per the NACE Standard. Hydrogen induced cracking test instrument is supplied with standard size of 12”(L) x 12”(W) x 9”(H). HIC testing apparatus is provided with specially made rack to keep the samples with minimum surface contact and all the specimens can be viewed during the test period easily. At the option of customer, we also supply custom custom size apparatus apparatus with spare glassware's, tubing, tubing, and accessories. accessories.
HIC test apparatus is suitable for standard e nvironment chamber is machined from clear, durable perspect / acrylic to permit instant visual observation of the specimen at all times. Glass with acrylic is also available at option of user. O-ring seals are provided to prevent any leakages from test apparatus. Individual test apparatus are tested with Hydro Test of Air before dispatch. Each HIC testing apparatus has one inlet, one outlet and one plug to remove test solution or conduct potassium idometric test as per the standard to verify concentration of test solution.
What is hydrogen induced cracking? Refer NACE Standard TM0284 All the test apparatus are manufactured to provide interchangeable connections and fittings. It complies with requirements of TM0284. Purpose of HIC test procedure is to study hydrogen induced cracking mechanism. HIC test apparatus is suitable to use NACE TM0284 specified Solution A or Solution B. Solution A is a cidified brine. Solution B is simulated seawater prepared in accordance with ASTM D1141. In either case, H2S is bubbled through the solution constantly throughout the test period. NACE TM0284 specifies test duration of 96 hours. The test requires evaluation of pH values of the test solution before exposure and after the exposure. HIC test specimens are cut into sections and examined under a microscope for hydrogen-induced corrosion 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) as per the NACE Standard. We are also able to provide spares, HIC test procedures of all the items within shortest time. Hydrogen induced cracking corrosion testing ( HIC Test ) made easy using Caltech;s HIC Testing Apparatus. Answer Of Questions Questions
Interesting question. I am not familiar with API codes, but have have some general metallurgical metallurgical comments. Hydrogen (and/or hydrogen hydrogen sulfide) causes different types of damage in in different materials. So, different tests for different materials & environments. For the lower strength steels commonly used in pipe and plate, hydrogen induced cracking (HIC) occurs when hydrogen atoms diffuse to internal defects and inclusions (voids, sulfide, carbide) where it forms molecular gases (H 2, CH4, H2S). This creates internal internal pressure which can can cause blistering and failure without any applied applied stress. The surface corrosion is a means for hydrogen to enter enter the
metal. HIC vulnerability decreases as the steel's strength increases. Thus, HIC testing for 96 hours w/o any applied loading per NACE TM0284 is used. Higher strength steels are vulnerable to hydrogen embrittlement (HE), where interstitial hydrogen atoms can cause damage w/o forming molecular gas. It greatly lowers the ductility of the steel under applied loading. Martensitic lattices are especially vulnerable. Corrosion isn't necessary for the 'pure' form of HE (unaccompanied by corrosion), also known as mechanical HE. Thus, high strength fasteners are tested under applied load per ASTM F519 or F1624. Sulfide Stress Corrosion Cracking (SSCC) is a combination of HE and SCC, where H 2S in a corrosive, wet environment is the source of the hydrogen. Vulnerability increases with steel strength and applied load. Corrosion is involved, so a longer testing period. Thus, testing per NACE TM0177 is performed under an applied load for 30 days (hence, $$$). You already know applications requiring SSCC testing. Suggest posting your HIC question on the API forum – forum809 Give the material & strength of the forging; (probably HIC testing if lower strength steel, SSCC if higher strength, but I don't know the dividing point). Also, if you are in Middle East or South Asia, maybe this lab can help: http://www.tcreng.com/
