High Temperature Fracture Stress of Standard Pressure Cast Steel
High Temperature Fracture Stress (HTCS) is an important element in the manufacture of pressure cast steel components and castings. The HTCS of a pressure cast steel material, in combination with other production variables like molding pressure and cooling rate, is a major factor in determining the quality, performance and physical characteristics of the parts and finished components.
HTCS measures the amount of energy needed to cause a pressure cast steel material to fracture. Generally speaking, the greater the HTCS value, the more energy is required to cause a fracture, and the greater the resistance of the material to high temperature failure. HTCS is often specified by product specifications as part of the design, testing and/or quality assurance process.
To determine the HTCS of a pressure cast steel material, a test specimen is subjected to a fixed temperature. The stress to cause fracture is determined by a destructive test requiring the sample to be heated in a heating chamber and the resultant stress is measured with a measuring device. The sample is cooled and the results are compared with different cast steel samples having different HTCS values. In order to obtain an accurate HTCS value, the specific conditions of the test sample must be maintained in a state of burnishing.
The HTCS value for each type of pressure cast steel can be determined by a single test or by a series of tests. Depending on the type of material being tested, or the desired final product, additional data about the HTCS value may need to be collected. For example, additional tests may be necessary to determine the HTCS values for fatigue environments or elevated temperature exposure.
In general, the HTCS values of standard pressure cast steels range between 40,000 psi and 80,000 psi. The values are dependent on various factors like the type of material, its composition, the type and size of the sample, the temperature range of the test and the method of evaluation.
HTCS values are also influenced by the environment in which the pressure cast steels are used. High temperature environments will reduce the HTCS of the steel, resulting in a decreased resistance to failure. Conversely, if the pressure cast steel is exposed to a colder environment, the HTCS values will increase, providing a greater resistance to failure.
The accuracy of the HTCS test results is influenced by many factors, including the method of testing, the environment in which the test is conducted, the size and shape of the test specimen and the testing process used. The HTCS results may also differ between different pressure cast steels of the same type due to differences in composition or manufacturing processes. It is highly recommended that industry standards are closely adhered to when conducting HTCS testing.
In conclusion, HTCS is an important characteristic of pressure cast steel materials. The HTCS value determines the amount of energy necessary to cause a fracture and is a major factor in determining the quality and performance of the final product. The results of HTCS testing can be affected by a variety of factors and must be conducted in accordance with industry standards.
