Galvanizing is one of the most effective and economic processes employed to protect steel against corrosion. The steel's zinc coating offers protection in two ways; firstly there is the barrier formed by the coating itself. The Second is cathodic (or sacrificial) protection, which occurs when the steel and zinc are simultaneously exposed. Working with this material since 1973. CSN supplies the market with hot dipped galvanized sheets, which can be submitted to the same manufacturing processes as similar non-coated materials. They can be welded, formed and attuned to various painting processes, as required.
CSN's galvanized steels are available to the market with the following specifications:
They are intended to simple formation and are basically used in parts where an enhanced level of mechanical properties is not required.
Steels for Stamping
Changes in its chemical compositions provide several grades of stampability, as medium for light formation parts, such as panels and girders, the extra-deep, for critical and complex parts, such as oil cart and wheel box (automotive industries.). In this sector, due to their excellent formability, IF steels (Interstitial Free) are noteworthy.
Pre-configured Blanks
They are blanks tailored composed, ready to final stamping. Usually seen in internal and external parts of the automobile body. Such cutting techniques optimize quality material transportation, reducing cost and weight, in addition to reducing material operation in customer's facilities. CSN Porto Real has a press line where blanks are tailored cut to the automotive industries, from Cold Rolled and Galvanized products.
Welded Blanks
Tailored blanks assembled by laser welding, allow the combination, in the same parts, of plates with different thickness, mechanical properties and finishing; CSN is the only steel plant to use this technique, optimizing component productions to the automotive industry, reducing costs and increasing vehicle safety.
Structural Steels
With a high mechanical resistance, they are mainly indicated for use in flat products and applications requiring plain bending, corrugations or light stamping, as bins, structural shapes for civil construction and bus structures.
High Resistance and High Formability Steels
Used in exposed panels, such as car doors, ceilings and hood, and structural parts of automotive industry, such as cross members and supports, they show mechanical resistance and formability and are usually supplied under previous technical consultation.
Bake-Hardening Steels
They also combine mechanical resistance and formability and are normally used for exposed panels. As they can become harder due to aging during painting cure, they make possible the reduction of the relationship thickness/weight, with no loss of indentation resistance. Their good formability is assured by the low initial values for yielding points. After stamping and par painting, the yielding point increases, giving it a mechanical resistance similar to the ones from high-resistance steels. They are produced under technical consultation.
Galvanew®
Galvanized plates obtained from hot dip and submitted to a later thermal treatment, which provides a coating totally constituted by a zinc and iron alloy. This structure give an excellent superficial aspect, making possible a better welding quality and a better adjustment to the painting as compared to plates with zinc only coating. They can be supplied with hardening rolling and oiling, specially for automotive sectors and household utiliies.
Galvanized Steel with Al-Zn Coating and Pre-painted
Two new products that CSN will start manufacturing through Cisa. The first one, which shall arrive to marked with a commercial name of Cisalum, is coated with an aluminum and zinc alloy that gets three main advantages: the resistance against oxidation, the beauty of aluminum and the strength of the steel. The second one, named Cisacolor, besides to be intended to other uses, shall arrive to the marked in the form of shapes and tiles ready for use in civil construction. Until the start of Cisa's operations, foreseen to the early 2003, CSN imports these products to meet national needs.
Galvalume Coil produced at CSN Paraná, in Curitiba.
