What are the testing methods and standards for machine tool castings?

Machine tool castings refer to the structural and functional parts of machine tools, usually made of cast iron or steel. In order to ensure the quality of machine tool castings, a series of inspections and tests are required. The following are commonly used machine tool casting inspection methods and standards.

1. Physical and chemical properties testing: The physical and chemical properties of machine tool castings are important indicators to evaluate their material properties. This includes hardness, mechanical properties, chemical composition and other tests. Commonly used physical and chemical properties test methods include tensile test, impact test, hardness test and so on.

2. Metallographic tissue detection: Metallographic tissue detection is to observe the tissue structure of the material through an optical microscope and evaluate its tissue morphology, grain size and other indicators. Metallographic microstructure inspection can reveal defects, non-uniformity and microstructure evolution of materials. The commonly used methods of metallographic tissue detection include metallographic sample preparation, metallographic microscope observation and image analysis.

3. Acoustic detection: Acoustic detection is to detect the defects and inhomogeneity inside the material through the propagation and reflection of sound waves. The commonly used acoustic detection methods include ultrasonic detection and pulse echo method. Acoustic inspection can detect defects such as pores, inclusions and cracks in castings.

4. Magnetic particle detection: Magnetic particle detection is the use of magnetic field and powder magnetic interaction to detect the surface and internal defects of materials. Common magnetic particle detection methods include wet magnetic particle detection and dry magnetic particle detection. Magnetic particle detection can detect defects such as cracks, pores and inclusions in castings.

5. Penetration testing: Penetration testing is the use of capillary action and adsorption on the surface of the material, through the liquid penetration into the surface defect of the material, and then through the action of color development agent or fluorescent agent to show the location and shape of the defect. Common penetration testing methods include wet penetration testing and dry penetration testing. Penetration inspection can detect defects such as cracks, pores and inclusions in castings.

6. X-ray detection: X-ray detection uses rays to penetrate materials and interact with absorbers of different densities, and determines the defects and internal structure of materials by detecting the absorption and diffraction of rays. Common X-ray detection methods include X-ray radiography, X-ray fluoroscopy and X-ray diffraction. X-ray inspection can detect the internal defects of castings, forging defects, heat treatment defects, etc.

The above is a commonly used test method for machine tool castings, and the test standard for machine tool castings is the specification to determine the test index and test method. Commonly used machine tool casting testing standards are as follows:

1. GB/T 229-2007 Metal material tensile test method standard at room temperature: The standard specifies the metal material tensile test method and requirements at room temperature.

2. GB/T 7233-2007 Impact test of metal materials impact bending test method standard: The standard specifies the impact test and bending test methods and requirements of metal materials.

3. GB/T 9444-2011 Metal materials microstructure inspection method: This standard specifies the methods and requirements for metal materials microstructure inspection.

4. GB/T 21844-2008 Ultrasonic test method for metal materials: The standard specifies the methods and requirements for ultrasonic testing of metal materials.

5. GB/T 94040-2007 Steel and alloy chemical analysis method: This standard specifies the method and requirements for chemical analysis of steel and alloy.

6. JB/T 4730-2005 Standard for non-destructive testing of steel and its products: This standard specifies the methods and requirements for non-destructive testing.

When testing machine tool castings, suitable testing methods and standards can be selected according to the actual situation. The test results will effectively evaluate the quality of machine tool castings to ensure their performance and safety.