Process Optimisation through Temporary Corrosion Protection
Corrosion doesn’t just become a problem when parts are used, but rather already during manufacturing, storage and transport. For this reason, temporary corrosion protection plays an important role for quality and cost-optimised manufacturing. Measures which make is possible to protect components from corrosion in a requirements-oriented fashion will be presented at the COROSAVE international trade fair for corrosion protection, preservation and packaging at the Stuttgart Exhibition Centre from the 20th through the 22nd of October, 2009.
Whether it results in the impairment of downstream work steps or customer complaints – corrosion may lead to scrap and thus significant economic losses. An overview of how the problem of corrosion can be kept under control in a requirements-oriented, efficient fashion during parts production, storage and transport will be offered by COROSAVE, which will be promoted by fairXperts GmbH concurrent to the leading international trade fair for cleaning within the production process, parts2clean, from the 20th through the 22nd of October, 2009. The exhibition portfolio covered by COROSAVE includes media, processes and equipment for corrosion protection and preservation, corrosion protection packaging, services for protecting surfaces against corrosion, measuring, test and analysis systems, services from the fields of test technology such as salt spray testing and environmental tests, science and research, technical literature, training and vocational education, as well as trade associations.
Corrosion Protection in Production
The process steps required for cleaning and temporary corrosion protection are so closely associated with each other that they can’t really be observed in isolation. For example, production steps such as degreasing and machining often result in extremely clean surfaces which are thus made
susceptible to corrosion. The use of aqueous machining media usually promotes corrosion as well. “Effective temporary corrosion protection is already required at this stage, in order to prevent costly scrap”, explains Hartmut Herdin, managing director of fairXperts.
Protection for a Few Hours up to Several Years
As opposed to permanent corrosion protection, the task of temporary protection is to preserve components during production, storage and transport. Time periods of a few hours up to several years are usually involved. In order to avoid interfering with downstream processes, it should be possible to remove protective coatings easily and completely. The industry offers various processes and products to this end.
So-called aqueous, temporary corrosion protection usually makes use of fatty acid and amine adducts. These substances are added to the last rinse after the cleaning or pickling bath, or to aqueous machining media such as coolant water, and form a dense film on metal surfaces which functions as an isolating layer. Volatility and the hydrophobic effect can be adjusted by selecting the appropriate substance.
An isolating layer between the metal and the environment can also be applied in the form of corrosion protection oils and emulsions, as well as grease and wax. The latter can also be applied as so-called dewatering fluids. Preservatives and corrosion inhibitors are incorporated into these temporary corrosion protection agents. Depending upon the layer thickness achieved by the application process, we speak of thin film (less than 1 µm) or thick film.
Another way to provide temporary corrosion protection is to influence the corrosive environment with packaging. The packaging functions as a barrier against aggressive environments and water vapour which might otherwise come into contact with the parts. In addition to metal and plastic containers, materials such as polyethylene and aluminium compound foils have proven their worth as packaging materials for corrosion protection. So-called drying agents and volatile corrosion inhibitors are used inside the packaging in order to create a corrosion inhibiting atmosphere. Commonly used drying agents include silica gels and activated clay granules. These are capable of absorbing water, and to some extent corrosive gases as well. Volatile corrosion inhibitors enter the gaseous state at room temperature. The VCI materials, which consist of powders, granules, liquids, impregnated foils, foams or paper, create a gas phase inside the closed package that protects against corrosion.
Concurrent Event: parts2clean
An essential prerequisite for effective temporary corrosion protection is parts cleaning, during which all particulates and film-like contamination, as well as fingerprints, are removed. This is the subject matter of parts2clean, leading international trade fair for cleaning within the production process and maintenance, which will take place concurrent to COROSAVE. This event presents the world’s most comprehensive offerings for systems, processes and process media for degreasing, cleaning, deburring and pre-treatment of parts, parts baskets and workpiece carriers, handling and process automation, cleanroom technology, quality assurance, test methods and analysis procedures, media treatment and disposal, job-shop cleaning, research and technical literature. Visitors will thus be provided with the opportunity of gathering information in a targeted fashion regarding solutions in the fields of cleaning and temporary corrosion protection with a single trade fair visit.