Hard film anti rust agents are formulated from film forming agents, rust stabilizers, rust conversion agents, composite anti rust agents, non-toxic organic solvents, etc. They can form dry hard coatings of various colors such as transparent, golden, and black by adjusting the formula. They are suitable for the protection of black and non-ferrous metals and are a convenient and practical technical means for metal rust prevention. Hard film rust inhibitors are divided into transparent film rust inhibitors and opaque film rust inhibitors based on whether the film layer is transparent. Compared with other rust inhibitors, transparent hard film rust inhibitors have the characteristics of thin oil film, good rust resistance, fast coating drying, transparency and aesthetics, and the production process is simple and the cost is relatively low. Transparent hard film anti rust agent can quickly form a dry and transparent anti rust film on metal surfaces. The oil film is easy to dry, not sticky to the hands, has good adhesion, is easy to apply, has strong rust resistance, and the oil film is uniform, thin and transparent, maintaining the good appearance of mechanical products, beautiful and bright. Transparent hard film anti rust agent can be used as a medium to long-term anti rust treatment material for steel metal parts, cast iron, copper, aluminum, galvanized sheet and other metal materials.
The use of hard film anti rust oil as a pre-treatment method is very beneficial for improving the anti rust cycle of metal parts, simplifying operations, and saving pre-treatment costs. Some hard film anti rust oils can be thinly applied (15 μ Below m) and with excellent anti-corrosion performance (salt spray resistance time ≥ 120h), electroplated parts such as shafts, oil cylinders, hard pipes, pull rings, clips, and spring pins of engineering machinery products, as well as exposed machined surfaces, can be protected with hard film anti rust oil to improve product appearance quality and eliminate early rust problems of components.
At present, the hard film anti rust oil we use in structural components has a thin coating (film thickness ≤ 10 μ m) Excellent adhesion (level 0), good anti-corrosion performance (≥ 5.5 months), no impact on product assembly after coating protection before component assembly, low construction cost, and other advantages are worth promoting and applying. In addition, the problem of rust generated during the storage of finished products in the garage can also be solved by applying a hard film rust inhibitor. For example, our company implements a complete machine repair hard film anti rust agent process for hydraulic hard pipes, slewing bearings, pins, hydraulic cylinder pull rod leakage parts, and other parts, without the need for shielding protection of adjacent components (if painting repair process is carried out, shielding protection is required). The hard film anti rust agent attached to the coating due to "fog oil" can be cleaned with solvent, making the operation simple and convenient. Compared with methods such as changing surface treatment processes and increasing varnish or topcoat protection, using hard film anti rust oil to achieve short-term rust prevention in metal structural components not only has the characteristics of thin coating and excellent adhesion, but also has advantages such as good corrosion resistance, low cost, convenient use, easy construction, easy removal, fast coating drying, good rust prevention effect, and uniform and beautiful coating film. After testing and on-site construction operations, the hard film rust inhibitor can meet the requirements of early protection before assembly and early anti-corrosion protection after storage in the construction machinery industry, and can be promoted and applied in the construction machinery industry. If there are visual defects such as bumps, scratches, etc. on the dried oil film of transparent hard film rust inhibitor, it can be cleaned by soaking or scrubbing with solvents such as gasoline, and then reapplied. Large structural components in the construction machinery industry inevitably encounter collisions during transportation, assembly, debugging, and other processes. Hard film anti rust oil can be cleaned with solvents and repainted without affecting the appearance quality of the coating. Therefore, hard film anti rust agents are worth promoting and applying in the construction machinery industry. Construction process of hard film rust inhibitor 1) Process flow: substrate cleaning, oil removal, rust removal → immersion coating, spraying or brushing with rust inhibitor → drying. 2) Substrate cleaning: Remove surface oil stains and hand sweat from the metal workpiece to be treated, and thoroughly dry it. Workpieces coated with anti rust oil are not allowed to have hand sweat or corrosive media residue on the metal surface. Rubber gloves must be worn when removing oil. 3) Application: According to the process requirements, oil application methods such as dip coating and brush coating can be used. Small components can be treated by soaking, spraying, and brushing, while large parts can be treated by spraying, brushing, and other methods to ensure that the oil film on the metal surface is uniform and completely adhered. 4) Drying: Natural air drying. After the hard film anti rust oil is dried, a uniform and transparent anti rust oil film is formed on the surface of the workpiece; After the oil film is completely dry, polyethylene film packaging can be used. During packaging and storage, it is important to avoid collisions between workpieces to avoid damaging the integrity of the oil film. It should be noted that after cleaning the substrate, the surface must be free of oil and moisture, otherwise the hard film rust inhibitor may not dry; During soaking treatment, the workpiece is directly immersed in anti rust oil for 0.2-2.0 minutes. When taken out, it needs to be drained above the tank liquid and dried before sealing and packaging. Analysis of the protective properties of rust inhibitors
The performance comparison of several protective materials (hard film anti rust oil, soft film anti rust oil, and protective wax) is shown in Table 1. The test selected a tinplate (70mm) × 150mm), after polishing and surface cleaning, brush or spray a layer of anti rust material for testing and detection.
The adhesion test is based on the GB/T9286-1998 "Cross cut Test for Paints and Varnishes Film" to determine the adhesion level of anti rust oil. The adhesion of hard film anti rust oil can reach level 1 or above, and in fact, the adhesion of hard film anti rust agent on the substrate has a significant impact on the anti-corrosion performance of the anti rust agent.
The anti-corrosion performance results of rust inhibitors were obtained through experimental analysis from two aspects: salt spray resistance and atmospheric corrosion resistance. The salt spray resistance test shall be conducted in accordance with SH/T0081 "Salt Spray Test Method for Rust Preventive Oils". A cyclic corrosion test chamber shall be selected to evaluate the difference in rust resistance performance of rust resistant materials on metal surfaces in accordance with SH/T0217 "Evaluation Method for Rust Degree of Rust Preventive Oil Test Coupons". Atmospheric corrosion resistance testing refers to the inspection of the difference in rust resistance of rust resistant materials on metal surfaces in natural atmospheric environments according to SH/T0217. Table 1 shows that the anti-corrosion performance of hard film anti rust oil is significantly better than that of soft film anti rust oil, and it can achieve the anti-corrosion effect of protective wax.
Application in the construction machinery industry
Due to the fact that the anti-corrosion performance of some domestically produced galvanized and chrome plated parts cannot meet the increasingly high requirements for appearance anti-corrosion, or due to changes in surface treatment processes (such as using QPQ instead of chrome plating, Dacromet, nano alloy instead of galvanizing, etc.), or the addition of surface protection processes (such as adding hard film rust prevention oil protection, adding topcoat or varnish protection, etc.). These existing surface treatment methods not only have weak rust resistance, but also have relatively difficult wastewater treatment, making it difficult to change the surface treatment process. Suppliers are required to have corresponding process means and capabilities. Generally, manufacturers need to produce through third-party production, and the process guarantee ability is poor.
After assembly, the surface of the components may experience bumps and early rusting. Some users use the process of adding varnish or topcoat to solve short-term corrosion problems, but this process is suitable for use after product assembly or after overall painting, and is not suitable for use when components enter the factory (i.e. before assembly). Due to poor adhesion of the varnish or topcoat on the smooth surface, it can affect component assembly or cause paint film detachment after component assembly. However, some machined surfaces (exposed after assembly) may experience early rusting after prolonged assembly and debugging, making it difficult to handle the entire machine during painting.
