Load test machines

Since 2002 we are the agent of Cormet in German language area.

  • CORMET Loading devices
  • CORMET Autoclaves and Test cells

Cormet provides various kinds of loading devices for stress corrosion cracking (SCC), sulphide stress cracking (SSCC), hydrogen induced cracking (HIC), fracture mechanical and fatigue studies.

Cormet’s workhorse for stress corrosion cracking tests is a PC operated electromechanical loading device. It can perform Slow Strain Rate Tests (SSRT), Constant Load (CL) tests and Low Frequency Cyclic Fatigue (LFCF) tests. The loading device can be used in ambient temperature, autoclave and high temperature gas environments. There are several models available of which the 10 kN, 25 kN and 50 kN instruments are the most popular. The operational principle of the versatile and flexible controlling software is based on sequenced load patterns that can be combined and connected in series.

The highest cyclic loading frequency of Cormet’s electromechanical instrument is about 0.1 Hz depending on the amplitude, loading mode and loading pattern. Servohydraulic or electrically operated loading instruments are needed for the higher cyclic frequencies. Cormet can integrate an autoclave into such a loading device or integrate the servohydraulic actuator with a Cormet autoclave.

The core of the HIC instrument is a glass container in which the specimens are assembled. However, the accessories including gas volume flow meters, water traps, draft cabinet, ventilation and gas neutralization tools make the instrument more complicated. The HIC testing procedures are described in NACE TM0284-2011.

Operation of four point bending (FPB) instruments is described in NACE TM0177-05 Method B, ASTM G 39-2011 and ISO 7539-2 (1989). The FPB tests are often performed in HIC testing containers.

Constant-load instruments are used for evaluation of critical stress in a given environment using the Time-to-Failure (TTF) value as a testing result. Standards NACE TM0177-05 Method A and ASTM G 47 – 98 (2004) describe how to perform the constant load tests. Cormet offers spring loaded and motor controlled constant load instruments.


An autoclave is basically a test cell for high-pressure and often high-temperature environments. Autoclaves can be used as static independent autoclaves and as dynamic autoclaves when connected to recirculation loops. Autoclaves as well as test loops can be manufactured from various materials: stainless steel is a standard material but more corrosion resistant materials such as Hastelloy and titanium are used, too. For low-temperature applications, autoclaves can be coated with Teflon too.

Autoclave geometry is typically cylindrical, but they can be manufactured in different forms depending on the application. A flow through cell is essentially a tube through which there is a water flow. Electrochemical sensors and corrosion probes are installed through the bottom and top lids.

Low-pressure test cells allow more freedom with the design because a cell does not have to contain the pressure. Test cells for Hydrogen Induced Cracking (HIC) are often large glass walled containers in which tests according to NACE TM0284-11 and TM0177-05 Method B are performed.

Autoclaves can comprise many instruments such as electrochemical tools, electromechanical and servohydraulic loading devices, mixers and rotating electrodes.

Top of Line Corrosion (TLC) instruments are used for studying the corrosion caused by condensed water in a pipeline. Cormet has a versatile TLC instrument with continuous bubbling and a cooled finger-type specimen.

Optionally, there is a small funnel under the specimen where water drops condense. This water can be taken out of the autoclave for chemical analysis or electrochemical tests can be performed on line in the funnel. Hydrogen permeation tests are performed according to ISO 17081:2004(E) using a two cell autoclave with a steel plate between them.




A corrosion reaction producing hydrogen takes place in one autoclave. Hydrogen permeates through the steel plate into the other autoclave, where the hydrogen content is measured using an electrochemical method. Cormet has built this kind of instrument for high-pressure high-temperature applications with a loading device applying stress on the steel plate. One can study the effect of pressure, temperature and stress on the hydrogen-permeation kinetics.







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