Caltech Engineering Services manufacture and supply four point bending SSC test jigs, and also test vessels to test and accurately determine the stress corrosion cracking susceptibility of metals in H2S service. Test rigs meet requirements of ASTM / NACE Standard TM-0316 and suitable to test material as per requirements of NACE MR0175. Main objective of this test is to evaluate materials for the service behavior or to screen alloys for service in a specific severe environment for an accelerated time. The 4-point bend SSC test is performed using ASTM G-39 and NACE TM0177 standards and now as per NACE TM-0316 Standard.
Each assembly is provided with ready to use connections fittings. Test rig is designed to accurately determine specimen stress requirements. Test specimen size 5mm-6mm, width 15-25mm, and with length of 130mm is suitable for testing four point bending specimens. Stress corrosion specimen as per NACE TM-0316 Standard is machined before putting in the test vessel. The dimesions are offenly choosen so that A= H/4.
Four point bend test jig comes with digital deflection meter attachment to measure accurate deflection. 4-point bend test jigs are fabricated from precision-machined stainless steel with high accuracy. Stress level can be easily adjusted using a workshop wrench on the tension-adjusting screw and lock nut. Four- point bends provide a uniform tensile stress over a relatively large area of the specimen
Test vessel with standard environment chamber is machined from clear, durable perspect / acrylic to permit instant visual observation of the specimen at all times. Glass with acrylic vessels is also available at option of user. O-ring seals are provided to prevent any leakages from test vessel. Individual test vessels are tested with hydrotest of air before dispatch. At a time maximum 8-10 sets of samples can be tested. This depends on thickness of material.
In the test vessel, solution of sodium chloride+ acetic acid or synthetic ocean sea water as per ASTM D1141 is used with known pH. Solution A, B or C can be used as per NACE TM 0316 Standards.
Samples are stressed as per NACE TM0316 specifications and immersed in the solution for the test period.
At the end of the test, samples are evaluated for cracks using magnetic particle inspection or standard metallographic test and pH of the test solution.
We have more than 25 years experience with specific industry and have depth practical expertise to cover a variety of corrosion problems that are encountered in industries such as oil and gas production, oil and gas transmission, energy conversion systems, and nuclear power systems.