Rust prevention of bearings is an important task, especially in the rust prevention between processes. For example, after acid washing, cleaning, and grinding of bearings in the heat treatment workshop, there are many other processes involved. When the product is not produced in a flow process, it must be stored in an intermediate warehouse after being processed in sequence. Therefore, the bearing rings stored between processes must be rust proof.

The following methods are generally used for rust prevention during the cautious machine process:

1. Immersion in rust proof tank

Immersing the bearing ring in a 5% sodium nitrite and 0.6% sodium carbonate aqueous solution has a good rust prevention effect, but it requires many rust prevention tanks and other equipment, takes up a lot of space, and management is also inconvenient.

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 up. This method has a shorter rust prevention period, usually only lasting 7-14 days, and during the rainy season, due to humid weather, it can only be maintained for 2-3 days

It must be reprocessed, requiring both labor and money.

3. Applying oil

Apply rust proof oil like a finished product. This method requires cleaning before executing the next process, which is quite cumbersome.

Introduction to new rust prevention process methods

After joint research and development with relevant manufacturers, years of production practice have shown that multiple improvements have been made to the rust prevention between processes, and the use of spray painting has a better rust prevention effect. Initially, a trial was conducted on the rust prevention of the rollers. The semi-finished and finished products were rinsed with sodium nitrite aqueous solution once a day. After 3 months, no rust was found in the sampling results. Now, the semi-finished bearing ring sleeve is treated with spray rust prevention, and the effect is the same. The spray rust prevention process is relatively simple, and its method is as follows:

1. Procurement and construction of equipment

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

2. Process methods

Rinse with sodium nitrite aqueous solution every morning. The aqueous solution is sucked out of the water tank by a water pump and connected to the showerhead through a rubber pipe. Rinse the bearing ring like a spray. The washed aqueous solution flows back to the water tank from the return ditch. At the upper layer of the water tank at the end of the return ditch, a filter screen is made with fine iron wire mesh and gauze to prevent textile dust and dirt from flowing into the water tank. The intermediate warehouse should be kept clean and of good quality.

The solution in the pool is tested every 2 days and supplemented based on the test results. The replacement period of the solution in the pool is different months, with a thorough replacement every 2 weeks from April to September, and a monthly replacement from October to March of the following year.

conclusion

Spray rust prevention is more convenient to manage and saves labor. In the past, it was not possible to use two people to prevent rust in the intermediate warehouse. Now, one person can also do other work, and the rust prevention effect is also significant. In March 2003, over 4000 balls of 7002136 and 3620 rollers were treated with spray rust prevention, which has remained very bright and rust free for over a year. In addition, there is also significant savings in the consumption of chemicals. In the past, the roller workshop needed to consume over 4000 kilograms of sodium nitrite per month, but now it only uses 200 kilograms, saving nearly half.

The spray rust prevention method has been tested and used by relevant manufacturers in recent years, and has been proven to be very suitable for semi-finished bearings with medium, large, large batches, and long cycles.