Read：23+
Date：2025-04-30 15:50:17
Author: DTI
Stress Corrosion Testing: A Comprehensive Introduction
Definition
Stress corrosion refers to the failure of metal in a corrosive medium under tensile stress. This type of corrosion typically propagates through the grains, known as transgranular corrosion. The failure process is the result of a combined action of strain and corrosion caused by residual or applied stress.
Purpose of Testing
The primary purposes of stress corrosion testing are:
-
To assess the stress corrosion sensitivity of materials in specific corrosive media.
-
To predict the service life of materials, providing a basis for maintenance and replacement.
-
To guide the selection and protective measures of materials, enhancing their reliability and cost - effectiveness.
-
To study the mechanisms of stress corrosion and develop new alloys with improved resistance to stress corrosion.
-
To evaluate the effectiveness of protective technologies, such as corrosion inhibitors and electrochemical protection.
Testing Standards
Commonly used international standards for stress corrosion testing include:
-
ISO 7539: Corrosion of metals and alloys - Stress corrosion testing.
-
NACE TM0177: Method for the evaluation of stress corrosion cracking resistance of metals in a specific environment.
In China, the commonly used national standard is:
-
GB/T 15970: Corrosion of metals and alloys - Stress corrosion testing.
Testing Methods
Stress corrosion testing involves various methods, including:
-
Constant Deformation Testing: Loading the specimen by applying a certain amount of deformation, with the crack propagation rate decreasing as the crack extends.
-
Constant Load Testing: Applying a specific load to the specimen using weights, torques, or springs, with the crack propagation rate increasing as the crack extends.
-
Slow - Strain - Rate Testing (SSRT): Stretching the specimen at a constant slow strain rate in a corrosive environment until fracture.
-
Fracture Mechanics Testing: Assessing the sensitivity to stress corrosion cracking by measuring parameters such as crack propagation rate (da/dt) and critical stress intensity factor (KISCC).
Testing Conditions
The conditions for stress corrosion testing include:
-
Stress Conditions: Magnitude, direction, and application method of the stress.
-
Corrosive Medium: Type, concentration, temperature, and pH value of the medium.
-
Environmental Factors: Such as temperature, humidity, and oxygen content.
Types of Test Specimens
Test specimens for stress corrosion testing are generally divided into smooth specimens, notched specimens, and pre - cracked specimens. Notched and pre - cracked specimens have advantages such as shorter incubation periods and better reproducibility.
Evaluation of Test Results
The results of stress corrosion testing are typically assessed using the following indicators:
-
Crack Initiation Time: The time it takes for a specimen to begin developing cracks in the corrosive medium.
-
Crack Propagation Rate: The speed at which cracks extend in the corrosive medium.
-
Critical Stress Intensity Factor (KISCC): The minimum stress intensity factor required for crack propagation.
-
Fracture Time: The time it takes for a specimen to completely fracture in the corrosive medium.
Conclusion
Stress corrosion testing is of significant importance for ensuring the safe operation of industrial equipment and extending its service life. Through this test, the corrosion behavior of materials under actual service conditions can be effectively predicted, allowing for appropriate protective measures to be taken.
Get Your Free Testing Plans and Quotation
Ask professional engineers for on-line service, and receive testing proposals within 2 hours.
Six Reasons to choose DTI
Complete qualifications
Complete range of qualification certificatesDTI has CMA, CNAS and other qualifications, including China's domestic and global relatively comprehensive leading qualifications at metal materials and corrosion test field. We can provide authoritative reports of national standard and industrial standard.
Viewing CertificatesProfessional team
70% professional and technical personnelDTI has a professional testing team, with 70% of professional technicians and 70% of undergraduate degree or above. From drafting proposals to sample analysis issuance, we are professional at each step to ensure the precision.
Learn MoreAdvanced Equipment
400 units with a 92% import ratioDTI has invested affluent budgets onto 450 sets of advanced large and medium-sized testing equipment. 92% of the equipment are imported from U.S., Germany, Switzerland, installed at scores of labs cover an area of 8,000 m2 and services cover 1000+ segments.
For DetailsAccurate Data
The accuracy rate of the inspection reaches 99%our professional technical testing team, advanced equipment, large number of databases, and solid implementation of lab quality control, DTI guarantees the overall accuracy rate of the reliable analysis data up to 99%.
consult NowComprehensive Service
One-stop tracking serviceDTI services cover the whole industries and provides the optimal solutions and technical support in terms of cycle time,cost-saving and qualifications based on numerous indicators, E2E supply chain solutions, all-round multi-dimensional product analysis.
Learn MoreCustomer Service
Regular return visits can be re-examinedDTI 24h*7 service (China) is available so that you could reach us anytime, anywhere. We also have an Emergency Service Access in case of special circumstance. DTI visits their customers regularly, and the questionable items in issued reports can be redone free of charge.
Online ServiceOnly Four Steps to Get Your Reports
Issues You May Care About
-
A. DTI has a comprehensive range of instruments and equipment, as well as numerous engineers with over 10 years of experience.
B. We offer consultative services with a broad industry scope, tailoring solutions to meet customer needs.
C. We provide one-stop technical services in the environmental field, with dedicated personnel throughout the process, allowing customers to stay informed about the progress of their reports in real time.
-
A. Normally, we will issue a report within 5-7 working days after receiving the samples.
B. To expedite the report issuance and eliminate extensive manual processing steps, DTI employs collaborative efforts across multiple departments and utilizes automated sample handling technology for certain types of samples, making the reports faster and more accurate.
C. For clients who urgently need the report, expedited services are available.
D. The report issuance time varies depending on the specific type of product, and you can consult with our online customer service for details.
-
DTI’s test data obtained from experiments are all true and valid, and will not maliciously alter or forge test data. The test reports issued by DTI are authoritative and credible and are recognized both in China and other countries.
-
The specific standards vary depending on the testing items. Please consult online customer service for details.
-
Our company promises that all test data obtained from the experiment are true and valid, and will not maliciously alter or falsify the test data. If any customer has any questions about the test data obtained from the experiment, please contact our technical staff, and our company will conduct a free re-inspection for the customer. If the data obtained after the replicated test are the same as the results of the initial test, our company will not change the test results. If they are different from the results of the initial test, our company will conduct multiple experiments on the samples during this period, and finally determine the results. Stable experimental data is used as the final test result.
-
Due to the large amount of standard information and other reasons, many customers may not know what items need to be tested. In this case, we could provide customers with recommendations for related projects, but the customers are required to provide the following information:
One-Stop Solutions Recommended
-
-
Shipbuilding Industry Solutions
-
Wind Power Industry Product Testing Solutions
-
Railway Industry Product Testing Solutions
-
Aerospace Industry Product Testing Solutions
-
Bridges and Steel Structures Product Testing Solutions
-
Laboratory and Research Institution Product Testing Solutions
-
Construction Industry Product Testing Solutions
-
Special Equipment Product Testing Solutions
LEARN ABOUT DING TESTING & INSPECTION
DTI has served thousands of entities, including numbers of Fortune Global 500 enterprises. DTI always conveys trustfulness to the quality life ubiquitously.
DTI is devotional on providing services for metal comprehensive testing. Among the testing services, DTI has more advantage at implementation of various corrosion resistance tests for different type of materials. The range of testing capability includes the analysis of metal composition and metal metallographic, mechanical performance and metal corrosion resistance testing, failure analysis, R & D analysis, and product quality assessment etc.
DTI has been awarded the conformity of assessment from ISO/IEC17025, ISO9001, GB/T28001/OHSAS18001, GB/T14001/ISO14001, CNAS and CMA Certification.
- 30
Industrial Fields
- 200Nos.
Large Equipment
- 3000㎡
Lab Area Size
- 1000Nos.
Customers Served
To be an influential, authoritative, third-party testing organization in China.
We provide professional inspection, testing, analysis for upstream and downstream supply chain of various industries, which covers industrial manufacturing, chemicals, offshore engineering, oil & gas, wind power, hydrogen energy, nuclear power, automotive structures, metals and minerals, equipment manufacturing, construction machinery, aerospace, etc.
We are committed to providing impartial, fair, accurate, and timely professional testing services nearly 20 provinces in China.
Learn more