ASTM E1457-19e1 Test for Measurement of Creep Crack Growth Times in Metals

ASTM E1457-19e1 Test for Measurement of Creep Crack Growth Times in Metals

ASTM E1457-19e1 test method is used to determine creep crack initiation (CCI) and creep crack growth (CCG) in metals at elevated temperatures using pre-cracked specimens subjected to static or quasi-static loading conditions. The standard values are stated in SI units.

    Scope:

    ASTM E1457-19e1 test method is used to determine CCG and CCI. The creep crack growth (CCG) rate, da/dt, is the rate of crack extension caused by creep damage and expressed in terms of average crack extension per unit time. The creep crack initiation (CCI) time is the time it takes for the initial crack to reach an extension of δai = 0.2 mm from the onset of the first applied force. This test method is applicable for base material with homogeneous properties and mixed base/weld material with inhomogeneous microstructures and creeps properties. Extreme environmental conditions can alter creep crack growth behavior, therefore, environmental conditions are carefully selected and maintained during the test. 

    Data gathered from this test can be used as follows:

    1. To generate models to predict crack incubation periods and growth using analytical and numerical techniques. 
    2. To determine the influence of creep crack development and growth on other component life under sustained loading and elevated temperatures where creep deformation might occur. 
    3. To determine material selection criteria and inspection requirements for damage tolerant products. 
    4. To calculate the individual and combined effects of metallurgical, fabrication, operating temperature, and loading variables on creep crack growth life.

    Test Procedure:

    In ASTM E1457-19e1 test method, the test specimen is sharply notched, fatigue pre-cracked, Compact Test specimen (CT). It is heated to the test temperature in a furnace. A load is applied to the test specimen. It could be in a three-point bending test or some other test method. The applied force is held constant throughout the test. The temperature is constantly monitored to ensure that it remains at the specified level within allowable limits during the test.

    Three different loading methods are available for creep crack growth testing. Dead weight loading is the best and the most commonly used method. Constant displacement and constant displacement rate loading are only used when working with extremely brittle materials. The test is carried out for a long time. Usually,  between 5000 to 10,000 hours to reduce crack tip plasticity and allow for steady-state creep cracking to take place. The crack size and force-line displacements are continuously recorded.

    Specimen size:

    The size of the specimen depends upon material availability, the capacity of the loading system, whether the specimen can fit in the heating furnace with enough room for extensometers, and adequate ligament size for growing the crack stably to permit the collection of crack growth data. 

    The notch can be machined in the specimen by electrical-discharge machining, milling, broaching, or saw cutting. Compact test specimen (CT) is the primary choice for the test specimen. 

    Data:

    The force, force-line displacement and crack size data are numerically processed to obtain the crack growth rate versus C*(t), Ct, or K relationship.

    OUR SERVICES

    Core Materials Testing Services

    Metrology

    A variety of microscopy and spectroscopy tools available for precise measurements from the nano to the meter scale.

    Metrology Testing Services POPULAR TESTS:

    TEM SIMS Profilometry

    Materials Testing

    ASTM and ISO standard and custom chemical, mechanical, thermal, corrosion tests, etc. for all materials metals, ceramic or polymers.

    Materials Testing Services POPULAR TESTS:

    Nondestructive Testing Electrical Testing Chemistry Analysis

    Product Testing

    Thousands of tests for product quality and reliability under heat, humidity, temperature shock, vibration, drop, electrostatic discharge.

    Product Testing Services POPULAR TESTS:

    Vibration Testing Humidity Testing Accelerated Aging

    Looking for Material Testing?

    We have already delivered 10000+ Material Test results to top companies

      Send us a request

        Process for testing
        •  

          STEP 01

          You share material and testing requirements with us

        •  

          STEP 02

          We ensure your sample pick-up in an ensured manner

        •  

          STEP 03

          We deliver test report to your inbox

          Let’s work together!

          Share your testing requirements with us and we will be happy to assist you.

          ddd Just share your testing requirements and leave the rest on us!
          • Free, no-obligation consultation
          • Guaranteed confidentiality
          • Quick turnaround time
          • Hassle-free process

            idea icon
            Want to connect with an expert before you leave?