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Inspection Methods for Prevention Sulfidic Corrosion Failures
Date: 15/12/2022 | read: 263

Sulfidic corrosion is a significant cause of issues and leaks that can lead to incidents in the refining industry. It potentially cause loss of property and injury to people, unplanned outages and early replacements.

What is Sulfidic Corrosion

Sulifdation Corrosion is a result of naturally occurring sulfur compounds found in crude oil. In the absence of hydrogen, corrosion due to sulfur compounds in the crude is thought to occur at temperatures above 500°F (260 °C). Up to that temperature, corrosion rates due to sulfidation are relatively low, even for carbon steels, unless there is naphthenic acid present in the crude. High temperature sulfidation is one of the most well-known corrosion mechanisms in the oil refining industry because it can occur in multiple sections of the refinery.

What Cause Sulfidic Corrosion

When exposed to hydrogen-free sulfidation corrosion conditions, carbon steels with low-silicon ,less than 0.10%  content can corrode at an accelerated rate. It is estimated that over 30% of high-temperature sulfidic corrosion failures are caused by low silicon content.

Inspection Methods for Finding Low Silicon Components.

Inspection methods for finding low silicon components vary, and programs differ from stripping all insulation, to the use of radiographic methods or long range guided wave UT methods to find all welds and selectively stripping insulation. This allows access to the piping on either side of the weld, as well as the weld itself.

Of course, rather than stripping insulation, there are more practical ways to perform baseline thickness checks. For example, one could use an X-ray imager to find welds and then cut a cookie in the insulation to check the thickness of each piping segment. Once the cookie has been cut, thickness checks can be done and positive material identification (PMI) could be performed. Pulsed eddy current (PEC) is also useful NDE technique for finding thin components without stripping insulation.

Beside the above mentioned, for the steel material PMI testing, XRF(X-ray fluorescence ) is an ideal method to determine the concentration of the low silicon. when exposed to hydrogen-free sulfidation corrosion conditions, carbon steels with low-silicon ,less than 0.10%  content can corrode at an accelerated rate.

Handheld XRF is Ideal to Determine the Low Silicon in Carbon Steel

Silicon analysis of this kind of equipment and piping using portable X-ray fluorescence (XRF) is an ideal choice to assist in the prevention of these incidents from occurring. Precise, accurate and fast analysis of silicon and other elements in for the crude oil and refinery field is enabled by AXR Scientific Handheld XRF Analyzer Terra900S.

Terra900S series analyzers provide a relatively complete solution for the composition analysis and reliability identification of alloy materials. The instrument is equipped with a high-performance X-ray tube and SDD detector to provide users with fast and accurate element content analysis; an optional large-area silicon drift detector is provided to further improve the resolution of the instrument and reduce the time required for analysis. And it has proved that Terra900S is the suitable solution for Analysis of Silicon in Steel to Prevent Sulfidic Corrosion Failures.

AXR Scientific is a high-tech manufacturer focusing on the development and application of X-ray technology products. It is committed to becoming a world-class supplier of X-ray industrial inspection solutions.AXR Scientific currently offer handheld XRF analyzer, handheld alloy analyzer, handheld soil analyzer, handheld lithium battery analyzer, precious metal analyzer, coating analyzer, gold analyzer and online XRF analyzer etc. to global customers. We keep serving global customers in the fields of machinery manufacturing, metal processing, aerospace, petrochemical, mining and geology, food safety, environmental protection, scientific research and etc. AXR Scientific keeps improving product performance and user experience with R&D advantages and innovative designs, and continues to provide global users with reliable X-ray measure solutions to solve various challenges from routine testing tasks to complex customized measure requirements. To contact us, please send email to