Corrosion occurs, which not only affects the accuracy and surface Rust Of Precision roughness, but also reduces the service life, and even scrapped and can not be used.
Bearing rust prevention is an important work, especially the rust prevention between processes. For example, there are many processes after acid pickling, cleaning and Rust Of Precision grinding of bearings in the heat treatment workshop.
When the product is not produced by flow, it will be stored in the Rust Of Precision intermediate warehouse after one-time sequential processing. Therefore, the bearing rings stored between processes must be rustproof.
The traditional method of using Rust Of Precision antirust oil as antirust paint and its shortcomings the following methods are generally used for antirust in bearing processes:
1. Immerse in anti rust tank
The bearing ring is immersed in the aqueous solution of 5% sodium nitrite and 0.6% sodium carbonate. The Rust Of Precision antirust effect is good, but many antirust tanks and other equipment are required, which takes up a lot of space and inconvenient management.
2. Dip coating concentrated sodium nitrite solution
After cleaning, immerse the product in a solution containing 15% – 20% Rust Of Precision sodium nitrite and 0.6% sodium carbonate, and then stack it.
Using this method, the anti rust period is short and can only be maintained for 7-14 days. Moreover, in the plum Rust Of Precision rain season, it can only be maintained for 2-3 days due to wet weather, so it must be reprocessed, which requires labor and money.
Apply antirust oil similar to antirust paint like finished products. This Rust Of Precision method must be cleaned before the next process, which is more troublesome.
Introduction of new antirust process
After tackling key problems together with relevant manufacturers, many years of production practice shows that the rust prevention between Rust Of Precision processes has been improved for many times, and the rust prevention effect of spray type is better.
At the beginning, the roller rust prevention was tried. The semi-finished products and finished products were washed with sodium nitrite aqueous solution once a day. After 3 months, no corrosion was found in the sampling inspection results.
Now the spray type rust prevention is adopted for the semi-finished products of bearing ring, and the effect is the same. Spray type antirust process is relatively simple, and the method is as follows:
According to the storage quantity of semi-finished products, an intermediate warehouse shall be established, with cement floor on the ground, and a walkway of about 1.5m can be set in the middle to pass the trolley of bearing ring. A water tank for storing sodium nitrite aqueous solution is placed at the end of the channel.
The solution formula is 5% – 10% sodium nitrite plus 0.6% sodium carbonate. A return ditch is made on the ground, and then the bearing rings are stacked on the floors on both sides.
A 0.6m walkway is reserved between each pile of bearing rings. It can be said that the design of the intermediate reservoir is about 64m2, and the water tank of sodium nitrite aqueous solution is 1m3.
2. Process method
Wash with sodium nitrite aqueous solution every morning. The aqueous solution is sucked out of the water tank by the water pump and connected to the shower head through the rubber pipe to wash the bearing ring like spraying.
The washed water solution flows back to the pool from the return ditch. At the upper layer of the pool at the end of the return ditch, a filter screen is made of fine iron mesh and gauze to flow textile dust into the pool. The intermediate warehouse shall be clean with good quality.
The solution in the pool is tested every two days and supplemented according to the test results. The replacement period of the solution in the pool is carried out according to different months. It is completely replaced every two weeks from April to September, and once a month from October to march of the next year.
Conclusion spray rust prevention is convenient to manage and save labor. In the past, it was impossible to use two people in the intermediate warehouse to prevent rust. Now one person can also do other work. From the perspective of rust prevention effect, it is also very significant.
More than 4000 7002136 and 3620 rollers were sprayed for rust prevention in March 2003. They have remained very bright and free of corrosion for nearly a year. In addition, the consumption of chemicals is also greatly saved. In the past, the roller workshop used to consume more than 4000 kg of sodium nitrite per month, but now it only uses 200 kg,
saving nearly half. The spray type antirust method has been tested and used by relevant manufacturers in recent years. It has been proved that it is very suitable for medium, large, batch and long cycle semi-finished bearings.