Metal fatigue test

Date：2022-03-22 13:51:59Views：981

Metal fatigue refers to the process that materials and components gradually produce local permanent cumulative damage at one or several places under the action of cyclic stress or cyclic strain, and produce cracks or sudden complete fracture after a certain number of cycles. When the material and structure are subjected to repeated and changing loads, although the stress value does not exceed the strength limit of the material, or even lower than the elastic limit, failure may occur. This failure phenomenon of the material and structure under the repeated action of alternating load is called metal fatigue failure. Stress amplitude, average stress and number of cycles are three main factors affecting metal fatigue.

Metal materials are the most commonly used materials in aerospace, military industry, nuclear power, petrochemical industry, machinery and other industries. The nature of fatigue failure under alternating load has an important impact on the safety of equipment.

Detection range:

Zinc coating, alloy coating, metal coating, electroplated coating, automotive coating, metal coating of light industrial products, high-temperature electrical insulation coating, wear-resistant coating, heat-resistant and anti-oxidation coating, atmospheric and immersion corrosion resistant coating, conductivity and resistance coating, restoration size coating, machinery department, iron and steel materials, steel pipes, alloy products, welding materials, steel ropes, fasteners, rolling shutter doors, kitchen supplies, various metal pendants, machine parts Pig iron, aluminum pipe, iron plate, iron pipe, ingot, billet, profile, wire rod, metal products, non-ferrous metals and their products, light metals, heavy metals, semi metals, rare metals and rare metals, etc.

Test items:

Rockwell hardness, surface Rockwell hardness, Brinell hardness, Vickers hardness, tensile strength, yield strength, elongation after fracture, reduction of area, elastic modulus / tensile modulus, bending test, room temperature impact, low temperature impact, crimping test, flaring test, flattening test, shear test, wedge load test, guarantee load, failure torque test, forging streamline observation of forgings, coating thickness, salt spray test, acid salt spray test Copper ion accelerated salt spray test, cyclic salt spray test, intergranular corrosion, welding procedure qualification, etc.

Test method:

1. High frequency vibration fatigue test method:

The high frequency vibration test uses the test equipment to generate the alternating inertia force with the characteristics of cyclic load frequency of about 1000Hz, which acts on the fatigue sample, which can meet the research on the fatigue performance of metal materials in service under the conditions of high frequency, low amplitude and high cycle environment.

2. Single point fatigue test method:

This method can approximately measure the fatigue curve and roughly estimate the fatigue limit when the number of samples is limited. It is applicable to the service of metal components under rotating bending load in air, room temperature and high temperature corrosion.

3. Lifting fatigue test method:

Lifting method fatigue test is a commonly used method to obtain the fatigue limit of metal materials or structures. On the basis of measuring the fatigue strength by conventional fatigue test methods, or when the fatigue strength of materials or structures with specified life cannot be measured directly by test, the lifting method fatigue test is generally used to measure the fatigue strength indirectly.

4. Fatigue test method of infrared thermal imaging technology:

In order to shorten the test time and reduce the test cost, the energy method has become one of the important methods of fatigue test research. Fatigue of metal materials is a process of energy dissipation, and temperature change is a very important parameter to study energy dissipation in fatigue process.

5. Ultrasonic fatigue test method:

Ultrasonic fatigue test is an accelerated resonance fatigue test method. Ultrasonic fatigue test can be carried out under different load characteristics, different environments and temperatures, which provides a good means for fatigue research.

Reference standard:

ASTM E18-08b、ASTM E10-08、ASTM A370-11、ASTM E384-11、ASTM E8/E8M-13、ASTM A370-12、ASTM E290-2009、ASTM A370-09、ASTM E23-12c、ASTM F606-11、ASTM F606M-11、GB/T 230.1-2004、GB/T 231.1-2002、GB/T 4340.1-1999、GB/T 228.1-2010、GB/T 229-2007、GB/T 245-2008、GB/T 242-2007、GB/T 246-2007、GB/T 3098.1-2010、ISO 6508-1:2005、ISO 6506-1:2005、ISO 6507-1:2005、ISO 6892-1998、 ISO 7438:2005、ISO 148-1:2006(V-notch)、ISO 8494-2004、ISO 8493-1998、EN ISO 6508-1:2005、EN ISO 6506-1:2005、EN ISO 6507-1:2005、EN 6892-1:2009、EN 10045-1:1990、EN ISO 8494-2004、EN ISO 8493-2004、EN ISO 8492-2004、DIN EN ISO 6508-1:2006、DIN EN ISO 6506-1:2006、DIN EN 10233-1994、JIS Z 2245-2005、JIS Z 2243-2008、JIS Z 2244-2003、JIS Z 2241-2011、JIS Z 2248-2006、 JIS Z 2242-2005。