New technology for preventing rust between processes of precision imported bearings

The bearing has rust, which not only affects the accuracy and surface roughness, but also reduces the service life, or even scrapped and cannot be used. The anti-rust work of imported bearings is an important task, especially the anti-rust between the working procedures. For example, after the bearings are pickled, cleaned, and ground in the heat treatment workshop, there are many other working procedures. When the product is not produced by flowing water, it must be stored in the intermediate warehouse after the processing is completed at a time. Therefore, the bearing rings stored between the processes must be rust-proof. Traditional anti-rust oil and anti-rust methods like anti-rust paint and their shortcomings generally use the following methods to prevent rust between bearing processes:

1. Immerse in the anti-rust tank

Immerse the bearing ring in an aqueous solution of 5% sodium nitrite and 0.6% sodium carbonate. The anti-rust effect is still good, but it requires many anti-rust tanks and other equipment, which takes up a lot of space and is inconvenient to manage.

2. Dip coating with concentrated sodium nitrite solution

After cleaning the product, immerse it in a solution containing 15%-20% sodium nitrite and 0.6% sodium carbonate, and then stack it. With this method, the anti-rust period is relatively short, generally only 7-14 days, and in the rainy season, due to the wet weather, it can only be maintained for 2-3 days before it must be reprocessed, which requires labor and money.

3. Oiling

Apply anti-rust oil similar to anti-rust paint like the finished product. This method must be cleaned before the next process, which is more troublesome.

Introduction of new anti-rust technology

After cooperating with related manufacturers, years of production practices have shown that many improvements have been made to the rust prevention between processes, and the spray-type rust prevention effect is better. Initially, the roller anti-rust was tested. The semi-finished products and finished products were washed with sodium nitrite aqueous solution once a day. After 3 months, no rust was found in the sampling test. Now the semi-finished bearing ring is sprayed with anti-rust, and the effect is the same. The spray-type anti-rust process is relatively simple, and the method is as follows:

1. Purchase and construction of equipment

According to the amount of semi-finished products stored, establish an intermediate warehouse, with a cement floor on the ground, and a walkway, about 1.5m, in the middle, which is used to pass the trolleys of the bearing rings. Place a pool of sodium nitrite solution at the end of the channel, the solution formula is 5%-10% sodium nitrite plus 0.6% sodium carbonate, and make a drain on the ground, and then stack the bearing rings on the floor on both sides Above, there is a 0.6m walkway between each pile of bearing rings. It can be said that the intermediate storage is designed to be about 64m2, and its sodium nitrite aqueous solution pool is 1m3.

2. Process method

Rinse with sodium nitrite aqueous solution once every morning. The aqueous solution is sucked out from the pool by a water pump and passed to the shower head through a rubber pipe to wash the bearing ring like a shower. The washed aqueous solution flows back to the pool from the backwater ditch. On the upper layer of the pool at the end of the backwater ditch, a filter is made of fine wire mesh and gauze so that textile dust and dirt flow into the pool. The intermediate storehouse should maintain the quality and cleanliness. The solution in the pool is tested every 2 days and supplemented according to the test results. The replacement period of the solution in the pool is carried out in different months, from April to September every 2 weeks, and from October to March of the following year, every month.

Conclusion The spray-type rust prevention is more convenient for management and labor-saving. In the past, it was impossible to complete the rust prevention with two people in the intermediate warehouse. Now one person can also do other tasks, and the rust prevention effect is also very significant. In March 2003, more than 4000 rollers of 7002136 and 3620 rollers were sprayed to prevent rust. It has remained very bright and free of rust for more than a year. In addition, the consumption of chemicals is also greatly saved. In the past, the roller workshop needed to consume more than 4,000 kg of sodium nitrite per month, but now it only uses 200 kg, which saves nearly half. The spray-type anti-rust method has been tested and used by related manufacturers in recent years, and it has proved that it is very suitable for medium and large-scale, large-scale, long-period bearing semi-finished products.