CR Products, the most fundamental cold rolled producrs, have been applied for not only automobiles, home appliances, and construction materials but also various kinds of industrial wquipment. Particularly, those which are used in various kinds of automobile parts take advantage of diversifying productivity for varied qualities, good workability, and a fine surface. Because it has the demerit of producing rust on the surface by reacting with air and moisture if not processed with a protective measure, such as paint or oil, on the surface, electroplated products or color coated products such as GI producrs or EG products have become widely used pursuant to a recent trend that requires high corrosion resistance for a long time and fine appearance. Cold rolled steel is produced by rollong hot rolled steel with two horizontal rolls after removing rust and impurities by acid pickling, after which the hardened cold rolled coils are sogtened by treatment and the surface smoothened, Typed of cold rolled steel include the acid rinsed, rolled and heat treared steel sheets as well as thosd coated by surface-trearment. Unlike other coated steel products with a protective layer that prevents rust from the reaction of steel and oxygen, cold rolled steel does not have a protective layer and is generally coarde with oil before being shipped out.

Sheet of this quality is for simple bending or moderate forming. Commercial stell can be bent flat upon irself in any direction at room temperature. It has a wide variety of, uses, including automotive panels, electrical home appliances, drums, pipes, farm implements, office supplies, building and civil work materials, and as base metal for various coatings.

Sheet of quality has a greater degree of ductility and is more consistent in perfomance than commercial steel because of higher standards in production, selection and melting of the sreel. It is suitable for automotive panels, audio-visual equipment, and heating apparatuses.

Sheet of this designation should be used when drawing steel will not provide a suffocoent degree of ductility for fabrication of parts wirh strangent drawing requirements, or applications that require the sheet be free from aging. This quality is produced through special steelmaking and finishing practices.It is suitable for automotive front panels and rear fenders.

Stabilized deep drawing quality products boast the highest quality in terms of workability. It is suitable for automotive parts that require complicated treatment such as front fenders or wire. As a non-aging deep drawing sheet made with Al-Killed, quality is guaranteed against extreme stretching or straning.

Generally, high tensile strength steel is a steel product with a tencile strength of 35Kg/mm©÷ or higher, and is categorized into 35Kg, 40Kg, 56Kg or 60Kg according to the standard. The numerical mark indicates the minmum tensile strength. High tensile strength steel is mainly used to make internal/extemal automotive panels with the dual purpose of improving fuel economy and the safety of cars, It improves fuel economy by reducing the plate thckness therefore making the car lighter, and ensures collision sagety with higher tensile strength than other types of steel.

Cold rolled high tencile strength steel is made by various manufacturing methods in order to obtain hjgh tensile strength. Even in the same grade with the same tensile tensile strength, high tensile strength steel is specified into three subcategories:"R"for Rephosphorzed, "E"for Extra Deep Drawing and "BH" and for Bake Hardening,

1.R: Rephosporized
A large amount of phosphorus (P) is adden to improve tensile strength, and the content [C] level is set between 200~600ppm according to the grade by using low-to medium carbon steel to be used for general purposes with proper much processing.

2. E: Extra Deep Drawing
A large amount of phosphorus (P)is added to improve tensile strength, and [Ti]and/or [Nb]are/is also added so that the content [C] level is obtained to produce ultra-low carbon steel (0.01% or below). which is used for extra deep drawing with heavy processing.

3. BH: Bake Hardening
This is similar to high tensile strength steel for extra deep drqwing, but contains a lesser amount of[Ti] or [Nb]. By changing the temperature of hear treatment, the actual property is similar to that of extra deep drawing but it must be used immediately after the productuin since its properties deteriorate sue to aging over time, (Developed for the purpose of improving the material whem the steel is painted at an auto company.)

1. PPT : precipitation
Also called managing steel, PPT contains a large amount of nikel, cobalt and molybdenum. Desired hardness can be achieved by heat treatment such as treatment. Characterzed by high thoughness and tensile strength, PPT is used to make construction materials.

2. DP: Dual Phase
DP is formed by the fusing of martensite and ferrite at a high temperature. With a lower yield point than solid-soluting hardening steel, if has a higher workability and is used as high strength reinforcement material.

3. TRIP: Transformation Induced Plasticity
TRIP is ormed by fusing of three diffenrent elements including austenite, bainite and ferrite. With a higher elongation ratio than solid-soluting hardening steel, it has higher process ability and is used as a high strength reinforcement material.

4. Pretex: PREcision TEXturing
Steel sheet products whose surfaces have been formed with textures of concave semi-sphercal textures to form proper lubricaring pockets and to reduce the friction coefficient, Features improved deep drawing, painting adhesion, and painting clearness.