The ultrasonic flaw detector for shell casings is the core testing equipment to ensure quality, which accurately identifies internal defects by penetrating materials with high-frequency sound waves. The following are standardized operating procedures and key technical points:

1、 Preliminary preparation work

1. Equipment status confirmation

Before starting up, check the integrity of the insulation layer of the power line, and the grounding resistance should be less than 4 Ω;

Verify that the probe connection cable is not damaged, and apply a special coupling agent to the contact surface between the wedge and the probe;

Preheat the equipment for 30 minutes to bring the transmitting/receiving module into a stable working state.

2. Calibration of standard test blocks

Select CSK-IA test block with the same material as the tested cartridge case;

Adjust the gain knob to achieve 80% full amplitude ripple on the bottom surface of the 50mm diameter;

Set a sound path compensation curve to eliminate errors caused by material attenuation.

2、 Testing implementation phase

1. Workpiece clamping and positioning

Use a dedicated V-groove fixture to fix the cartridge case, ensuring that the axis coincides with the center of the probe;

Mark the starting position of the detection and keep the probe scanning at a constant speed (recommended speed ≤ 50mm/s);

Focus on scanning stress concentration areas such as the threaded area at the bottom of the cartridge case and the transition area at the neck.

2. Dynamic parameter adjustment

Adjust the time gate based on real-time waveform: the initial wave width is controlled in the 10% area on the left side of the screen;

Optimize the suppression level to eliminate clutter and retain effective defect signals;

Amplify and observe suspicious waveforms, and use peak memory function to lock in the highest echo.

4、 Data Management and Recording

1. Digital archiving

Automatically save A-scan waveform diagram, label the detection date, shift, and operator number;

Establish a defect database to track the distribution patterns of defects across different batches.

2. Physical identification traceability

Spray fluorescent marking paint on qualified products;

Unqualified products should be labeled with a red rejection label, indicating the location and code of the defect.

5、 Post homework maintenance

Exit the detection software before turning off the host power;

Clean the probe chip with non-woven fabric dipped in alcohol;

Replace the deionized water in the water tank every month to prevent scaling from affecting the coupling effect;

Quarterly replacement of launch board capacitors to maintain system stability.

The entire operation process requires strict implementation of a two person mutual inspection system, with the main operator responsible for instrument control and auxiliary workers for workpiece flipping coordination. When encountering controversial waveforms, reference spectra of historical products of the same specifications should be retrieved for comparative analysis.