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I. Basic Requirements and Operating Procedures for Self-Reinforcement Treatment (1) Basic Requirements: Verification of Material Properties Before carrying out self-reinforcement treatment, it is necessary to thoroughly verify the performance reports of the component materials to ensure that their properties meet the requirements for such treatment. The pressure requirements for the equipment dictate that the upper pressure limit of the self-reinforcement treatment device must be higher than the pressure required for the self-reinforcement treatment, with a certain margin left to ensure the safety and effectiveness of the treatment process. Testing instruments that have undergone self-enhancing calibration procedures must be regularly calibrated as specified, and should be used within their valid period to ensure the accuracy of the test data. Personnel qualification requirements stipulate that enhancement treatment personnel must undergo professional training, be familiar with the operational procedures, and possess the necessary operational skills as well as safety awareness. The manufacturing unit responsible for developing the process procedures shall prepare written self-reinforcement process procedures that cover at least the following aspects: the timing and methods for self-reinforcement treatment ； Methods for controlling self-reinforcing programs ； Method for recording time, temperature, and pressure during self-reinforcement operation ； Methods for measuring the degree of self-amplification and determining whether this degree is within acceptable limits. (II) The operational procedures specify that the process equipment should be connected in accordance with the requirements set out in the design and process specifications ； Connect sensors or attach strain gauges at the positions specified for the components ； Connection processing system ； Adjust the measuring instrument ； Load and check the sealing performance ； Record data such as time, pressure, displacement, or strain ； Uninstall, inspect. Pressure and safety requirements: The container must be fully assembled and passed inspection prior to the pressure test. For temporary pressure-bearing components installed for the purpose of conducting the pressure test, appropriate measures must be taken to ensure safety ； The manufacturing unit must establish strict testing procedures and requirements. The testing site should be equipped with reliable safety protection facilities and appropriate fire-fighting equipment; there should be no sources of fire in the vicinity, and the site must be inspected and approved by the unit’s technical supervisor and the safety and technical department ； During the pressure test, two pressure gauges with the same range and still within their calibration validity period should be installed at the top of the container or testing apparatus under test. The range of these pressure gauges should be 1.5 to 2 times the test pressure; their accuracy must be at least 1.0 grade, and the diameter of the dial must be no less than 100 mm ； During the voltage withstand test, unauthorized personnel are not allowed to stay at the test site. The actual pressure during self-reinforcement treatment must not exceed the specified value. Other requirements regarding the site and safety shall be in accordance with the provisions for voltage withstand testing: With regard to strain control, appropriate methods must be employed during the self-reinforcement process to control the residual circumferential strain on the inner wall of the cylinder, such that the permanent circumferential strain resulting from the self-reinforcement treatment on the inner surface shall not exceed 2%. II. Self-reinforcement methods and their characteristics (1) Basic principle of mechanical extrusion: A sliding conical mandrel with an interference fit is used to pass through the inner wall of a cylinder, thereby compressing the inner wall and inducing plastic deformation and residual stresses, thus achieving self-reinforcement. The shaft is pushed to slide by using a punch and a hydraulic press to press it in (indirect hydraulic method) ； Hydraulic pressure is introduced to the back side of the mandrel to directly push it ； Pulling the mandrel mechanically is known as mechanical traction. Its features are mainly applicable to open cylindrical (tubular) shapes; it is cost-effective, does not require external restraining molds, and has a relatively simple sealing mechanism ； The residual stress of 1500 – 2000 MPa can be achieved, limited only by the compressive strength of the mandrel material and not affected by the strength of the cylinder ； At specific radius ratios, for materials with the same yield strength, the pressure required is significantly lower compared to the hydrostatic method ； Although theoretically the circumferential residual stress generated should be lower than that in the hydrostatic method, the actual result is the opposite. This is because the hydrostatic method reduces the residual stress resulting from self-reinforcement due to the Bauschinger effect, whereas the extrusion method achieves a greater residual stress by inducing a smaller reverse yield through a combination of triaxial deformation. (II) Basic principle of the direct hydrostatic method: Liquid pressure is applied directly to the inner wall of the cylinder, causing it to undergo plastic deformation and generate excess strain; once the pressure is removed, residual stress is formed, thereby increasing the material’s elastic strength limit and fatigue life. Its characteristics are roughly the same as those of the hydraulic testing process for containers; it is easy to operate and flexible, does not require special pressure components, and enables uniform plastic deformation of the wall surfaces. It is particularly suitable for self-reinforcement of closed containers, while for open cylinders, end sealing devices can be used ； The self-inflation process requires ultra-high pressure sources, ultra-high pressure pumps, as well as ultra-high pressure pipes and related accessories; it needs to address the issue of sealing under ultra-high pressures, and is often limited by its range of applicability.