HIC Test Control Samples for Sour Service Accuracy
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Solution Overview
Problem
Current HIC testing methods for steel alloys in sour service applications lack accuracy due to deviations from standardized test conditions, leading to unreliable results and potential catastrophic failures in oil and gas equipment.
Innovation Solution
The use of prequalified HIC susceptible control samples subjected to the same test conditions as the HIC resistant material candidates ensures accurate validation of HIC resistance by meeting predetermined cracking criteria, thereby guaranteeing the validity of test results and minimizing the risk of substandard material approval.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If standardized HIC testing is performed without control samples, then testing procedure is simpler and faster, but test result accuracy and reliability deteriorate
Solution Approach 1:
The patent introduces control samples as an intermediary element in the HIC testing process. These control samples with known HIC susceptibility serve as a reference standard against which test samples are compared. The control samples act as a mediator to validate that testing conditions are appropriate and to calibrate the interpretation of test results, thereby improving measurement precision without fundamentally changing the testing procedure
Solution Approach 2:
The patent creates control samples that are copies or replicas of actual steel alloy materials but with known and controlled HIC susceptibility characteristics. These control copies allow for repeated testing under identical conditions to establish baseline data and verify test consistency, enabling accurate comparison with test samples while maintaining procedural simplicity
2Reliability
If HIC testing is performed on steel alloys for sour service applications, then material suitability can be assessed, but deviations from standardized test conditions lead to unreliable results
Solution Approach 1:
The patent implements a feedback mechanism where control samples are tested alongside test samples under identical conditions. The known characteristics of control samples provide feedback information about whether testing conditions are appropriate. If control sample results deviate from expected values, it indicates test condition deviations, allowing for correction before interpreting test sample results, thereby ensuring reliability and manufacturing precision
Solution Approach 2:
The patent requires that control samples be prepared and tested in advance or concurrently with test samples to establish baseline expectations for proper test conditions. This preliminary action of having predetermined control sample results available allows for verification of test condition consistency before final test sample evaluation, preventing unreliable results from being generated
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the accuracy of HIC testing by ensuring that only materials meeting specific HIC resistance criteria are qualified for sour service applications, reducing the risk of equipment failure and ensuring the integrity of oil and gas infrastructure.
Implementation Method 1
hydrogen atoms generated by the corrosion infiltrate and diffuse into steel to thereby be present in an atomic state in the steel
Implementation Method 2
While the hydrogen atoms in the steel, as described above, are molecularized in the form of hydrogen gas, a gas pressure is generated, causing brittle cracks to occur
Data Source
AI summary
A test sample is extracted from a hydrogen induced cracking (HIC) resistant material candidate. A control sample is extracted from a prequalified HIC susceptible material that is known to suffer predetermined HIC damage when subjected to preset test conditions of a standardized HIC test (e.g., NACE TM0284). The HIC test is performed on the test and control samples. A value of a predetermined cracking criteria is calculated for the control sample. It is determined whether the calculated value of the predetermined cracking criteria is at least equal to a predetermined minimum threshold value. If yes, respective values of a plurality of predetermined HIC resistance criteria for the test sample are calculated. It is determined whether the calculated respective values of the plurality of predetermined HIC resistance criteria for the test sample are not greater than corresponding predetermined maximum threshold values. If yes, the HIC resistant material candidate is qualified as a valid source for sour service applications.