The spring washer 65Mn material made of stainless steel is a high-strength steel wire, which is very suitable for spring washers. Many kinds of spring washer materials in China use 65Mn. Due to the poor anti-rust performance of 65Mn material, in order to enhance the anti-rust ability of the spring washer, it is usually necessary to carry out galvanization or cadmium surface treatment, which poses a hidden danger of hydrogen embrittlement of the parts. Therefore, under the premise of ensuring the elastic requirements of the spring washer, changing the spring washer material to avoid galvanizing or cadmium surface treatment is another way to solve the hydrogen embrittlement problem of the gasket. At present, the successful method is to change the material of the spring washer from 65Mn to special stainless steel materials, and there are successful cases at home and abroad. In order to solve the hydrogen embrittlement problem of 65Mn spring washers, the Shanghai Spring Washer Factory has succeeded in developing stainless steel spring washers with special 1Cr18Ni9Ti materials. The stainless steel spring washers have been adopted in the aerospace industry. In recent years, some manufacturers of aviation industry have used this stainless steel 1 spring washer, which is in good condition. No problems such as hydrogen embrittlement crack, poor elasticity and rust have been found in use. Our institute also used some stainless steel spring washers on a certain key model, and no quality problems have been found so far. It is recommended that other products that are still suffering from the hydrogen embrittlement of spring washers can also be used in place of 65Mn spring washers.
At present, there are fewer varieties of stainless steel spring washers developed in China and used by the industry to rise to the above standards. The existing varieties and standard substitutions are as follows: QJ2963.2-1997 "Special spring washer standard stainless steel spring washer" Instead of GB/T93-1987 "standard spring washer"; QJ2963.3-1997 "special spring washer light stainless steel spring washer" can replace GB/T859-1987 "light spring washer". These varieties and materials are available. Try to avoid galvanizing or cadmium plating. At present, various commercially available spring washers are basically made of 65Mn material. Since this gasket is galvanized or cadmium-plated, most surface treatment processes are difficult to achieve. With the complete elimination of hydrogen, the possibility of hydrogen embrittlement of spring washers still exists. Therefore, when the anti-rust requirements of the product are not high or the gasket does not work directly under harsh environmental conditions, such as in a sealed compartment (in a sealed box), the product design should avoid the requirements of galvanizing or cadmium plating on the gasket. Changed to other anti-rust treatments, such as oiling, surface oxidation, etc., which can prevent the hydrogen embrittlement of the gasket.
The rubber-proof anti-loose replaces the spring washer to prevent the loosening of the threaded connector. In the past, most of the spring washer structure was used. In recent years, the adhesive technology has been greatly improved. Some grades of adhesives such as Loctite and Iron Anchor have been Successfully used on the glue of the threaded connector to prevent loosening. At present, some aviation manufacturers' products have successfully replaced the spring washers with thread-coated rubber and anti-loose. The product has not been found to have quality problems after testing and use evaluation. Our institute has also successfully replaced the spring washer with thread-coated rubber anti-loose technology in a key model project. No problems have been found after rigorous testing and use assessment. There are two ways to apply the thread: the screw is assembled on the assembly site, that is, the thread is first glued and then screwed into the thread. Compared with the spring washer assembly, this method is cumbersome, requires cleaning parts, and proper screwing speed. The advantage of on-site gluing is that different types of thread strength can be selected according to different thread connection conditions (force size, detachability, connection structure, etc.).
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