What are the general methods of forgings surface rust prevention?

Forgings after heat treatment, first need to clean the table, remove the residual salt, oil stains and dirt on the surface of the forgings, and then use sandblasting or shot blasting means to remove the oxide and other oxides that are difficult to remove, the last link is the surface rust treatment of the forgings. Surface anti-rust treatment, including anti-rust preparation and the use of anti-rust oil anti-rust treatment two stages.

First, the preparation work before rust prevention

Although the forgings have been cleaned and cleaned after heat treatment, the surface of the forgings should be cleaned again before rust treatment. Because in the process of forging turnover, forging surface will also be contaminated by oil (because there is usually oil collapse in the transfer box). For precision forgings, operators in hand handling, will also be hand sweat on the forgings table, the surface pollution must be completely eliminated before rust prevention.

The preparation work at this stage is exactly the same as the surface cleaning process described above and will not be repeated.

Two, anti-rust oil anti-rust

The use of antirust oil for antirust, oil or resin substances as the main body, and then add oil soluble corrosion inhibitor composition of temporary antirust coating, its antirust effect is mainly manifested in the following aspects:

1. The dispersed corrosion inhibitor molecules in the oil film can be directionally adsorbed on the metal and oil surface to form a multi-molecule interface film, which has a shielding effect on corrosion factors.

2. Antirust oil has hydrophobicity, can replace the moisture stability in the oil.

3. It can improve the absorption force of oil film to metal, increase the resistance and reduce the activity.

4. Can inhibit the formation of corrosion battery, can prevent atmospheric corrosion.

In antirust operation, antirust oil is usually cold coated, and antirust grease is usually hot coated. When hot dip coating is used, the temperature should be reduced as far as possible to increase the thickness of the oil film, and the anti-rust effect of the forgings can be greatly improved with plastic film packaging.

Three, the choice of anti-rust oil

According to the different mechanical processing process, the anti-rust after heat treatment can be temporary anti-rust between the process, but also can be the final anti-rust of the finished product, the requirements of both are different, the selection of anti-rust oil is not the same.

The selection of anti-rust oil between the process, should consider the forging in the processing and turnover process and the operator's hand contact, easy to produce fingerprint rust on the surface of the forging, at this time, it is best to choose replacement type anti-rust oil. Its quality requirements should meet the SH/T0692-2000 no. 4 replacement antirust oil standard. In its performance index, human sweat changing and human sweat washing are the key points.

Sometimes, because the forgings can not be timely turnover, the need to overlap storage in the middle warehouse, but also to avoid overlapping surface rust or overprinting, especially cast iron products.

The length of the rust prevention period for the sealing of finished products depends on the factors such as whether the products are overstocked in the factory or whether they can be sold in time, whether they are used directly or stored for a long time. Product sealing commonly used anti-rust oil, solvent dilution type anti-rust oil, lubricating oil type anti-rust oil, grease type anti-rust oil and gas phase anti-rust oil. The quality shall meet the standard of SH/T0692-2000.

In addition, export products need to be transported by air, sea to the tropical or cold zone area, then also need to play according to the structure of the product and material to choose anti-rust oil.