Product Introduction
The plate mill is mainly equipped with the walking-beam continuous reheating furnaces, high-pressure descaling box, 4-high reversing rolling mill with hydraulic AGC system, γ-ray thickness gage, 24m-long on- line accelerated cooling system, 3600-tonleveler, rolling-disc type cooling bed, on-line automatic ultrasonic testing system, and normalizing furnace.1 million tons of plates are produced annually with the dimensions of 6 to 90mm in thickness, 1524 to 3800mm in width, and 3048 to 18000mm in length.CSC’s plates are used in manufacturing construction structures, shipbuilding, bridges, line pipes, machine structures, pressure vessels, and plate products with atmospheric-resistance and corrosion- resistance.Due to the excellent process control in the mill, CSC’s plates have better thickness and flatness tolerances than those specified by most of the international standards.
China Steel has been upgrading its production technology actively in terms of developing products with high quality and functions.Some of the developed products are as follows:
- High-strength plates for ultra-heavy constructionstructural use: They are plates with tensile strength of 570Mpa and more, thickness up to 80mm, low yield/tensile ratios, narrow strength ranges, and good weldability.They were used as the steel frames in the skyscraper of the Taipei Financial Center.
- Extra Low Yield Vibration-resistant Plates (CSC LYS100):They are plates with the yield strength lower than 130Mpa; they are suitable materials for vibration-prohibiting parts including shear walls, energy absorbers, etc.They can function as earthquake energy absorbers which will enhance the safety of a main structure body.They were used in building the Ambassador Skyscraper, a building with an earthquake- resisting design, in ShinJu.
- High-strength plates for line pipe use: They are plates with high strength and low temperature toughness; they are suitable materials for line pipes and gas-carrying pipes.They wereused in the Chinese Petroleum Corporation’s construction work of manufacturing pipes for carrying undersea liquid natural gas.
- Sulfur dew-point corrosion-resistant plates (CSC SCR-TEN3):They are plates with sulfuric acid and hydrochloric acid dew-point corrosion-resistance; they are suitable materials for building chimneys and funnels of incinerators.They were used in the construction work for building incinerators in Kang-shan, Jia- yi, and Yi-lung.
Both steel bars and wire rods are rolled from reheated billets. CSCsupplies bars in two forms, namely straight bars and bars in coils, with the available nominal diameters from 5.5mm to 13mm for straight bars and from 14mm to 55mm for bars in coils.The rods are in a coil form only, with the available nominal diameters from 5.5mm to 13mm.The total annual production for both is around 1.77 million tons, of which the product assortmentsare 35% for low carbon steel, 18% for medium high carbon steel, 26% for cold heading steel, and 21% for low alloy steel.
By the application of different processing techniques, steel bars and wire rods can be used for manufacturing general structures, machine structures, hard wires, and weld electrodes, and so on; they are also ideal materials for products which demand cold heading processing and hot forging processing.To meet the requirements of automated production and theupgrade of product quality for CSC’s downstream customers, CSC has developed spheroidized products that are suitable for direct cold heading use.Theavailable products are SCM435 for automobile bolts, 50BV30 for hand tools, S2 for air- driven screwdriver heads, 36CrNiMo4 for air-driven sockets, and SNCM439 for cold forging chisels.CH1A and CH1T, extra low carbon cold heading steel with excellent cold heading and deep drawing quality, are suitable for the production of rivets and speaker tips. AISI 1018AK is a product with good internal cleanness and cold heading quality.NLP33K (for non-lead patented heat treatment steel) is a product with good quench strength and the feature of being able to be flattened easily. Both AISI 1018AK and NLP33K have helped to build Taiwan to become the kingdom for the production of tapping screws and umbrellas in the world.NLP77B and NLP82B are both materials for non-lead patented pre-reinforcing steel strand wires.AWS-EM12K and EH14 are materials for automatic submerged arc welding wires for steel structures, and SXXC S1 for resulfurized free cutting steel.All of the aforementioned products have been successfully developed to meet the demands of the downstream users, and they have all contributed a great deal to the upgrade of the industry in Taiwan.
The hot rolled plant whose annual production capacity is 7 million tons operates on two lines of hot strip mills. In addition to the basic rolling facilities, it is equipped with a variety of cutting-edge facilities such as the edge heater, the hydraulic automatic gage and width control system, the work roll bending system, the work roll shift system, and the automatic profile and flatness control system. It is one of the most competitive plants in the world because the quality of our products has reached international standards. Hot- rolled products are made from slabs which are reheated in the reheating furnaces, rolled in the roughing mill and the finishing mill, cooled in the laminar spray way, down coiled into hot bands, and delivered to the hot-rolled finishing mill for skin pass, crop shearing, inspection, weighing, packaging, and marking. Presently, the types of hot-rolled products CSC supplies are hot-rolled bands(or hot-rolled coils, non-skinpassed), hot-rolled coils, hot rolled plates, hot rolled sheets, and hot-rolled pickled and oiled coil. The available sizes are 1.20~5.99mm in thickness for hot-rolled sheets, 1.20~6.50mm for hot-rolled coils, hot- rolled pickled and oiled coils, 2.00~12.7mm for hot-rolled bands, 6.00~12.7mm for hot-rolled plates, and 850~1,860mm in width for all types except hot-rolled pickled and oiled coils which range between 860~1,540mm.
Having the quality of being able to be made into various parts of complicated shapes because of their strength, tenacity, and weldability which enables CSC's hot-rolled products to be combined with other metal frames, CSC's hot-rolled products are widely applied in producing automobile frames, bridges, construction structures, freeway fences, pipes, pressure vessels, and gardening tools, etc. CSC supplies steel products with various classifications which include general low carbon steel, structure steel, high strength low alloy steel, and stainless steel. ACR-TEN AF( atmospheric resistant steel with formability), ASTM A214( steel for heat-exchanger use), API 5L/X52~X60( Line pipe steel with high quality), SAE 413 ( chromium-molybdenum steel), S55C,S60C( medium high carbon steel), SAPH series( steel for automobile structural use), SPFH series( steel with improved formability for automobile structural use), and SPHD( steel with non-drawing quality) are products with distinguishing features. These high quality hot-rolled products can satisfy the demands of our downstream customers and assist them in upgrading their competitiveness as a result.
The annual production capacity is 1.8 million tons with the available sizes of 0.30~3.20mm in thickness, 850~1,650mm in width for carbon steel, and 0.55~1.60mm in thickness, 850~1,260 in width for high strength low alloy steel.
The following are the distinguishing features and application of cold-rolled products:
- Luster: CQZ and DQ with bright and fine luster can be used as fundamental materials in producing automobile body parts, and home appliances which demand excellent appearance quality.
- Diversity and mechanical uniformity: CQS can be used in producing steel drums, and CQ1 in producing piping. SPCE( extra deep drawing mild steel) can be used in producing automobile parts which demand strict processing. High strength steel can be used in producing structures or reinforcing parts.
- Expansibility: After cold rolled products are processed, they can be further treated with heat, e.g. carburization or nitrocarburization, to make their surfaces hardened and more abrasion resistant. Grade S35CM, medium high carbon steel, can be used in producing chains. Grade SPP, low carbon heat- resistant steel, can be used in porcelain enameling treatment. All grades of steel can be surface coated by coating, electrogalvanization, or pre-lamination to expand their application. CSC will keep on producing cold rolled products with higher surface quality, better formability, and higher strength levels to meet its customers requirements.
With the production capacity of 150,000 tons per year, colored steel coils are made from 0.15~1.20 mm of cold-rolled coils or galvanized coils as base metals, which are processed with surface phosphate or chromate coating treatment, and then topped with dual layers of fine baking paint with synthetic resins. The available sizes for coils are 0.15~1.20 mm in thickness and 650 mm~1,300 mm in width. Colored steel coils possess the features of acid resistance, heat resistance, atmospheric resistance, corrosion resistance, and pollution resistance, and are suitable for general work on forming. The available product classifications are colored pre-painted coils (PE, SMP, PVDF), embossed coils (PVC PLASTISOL), printed coils, and PVC laminated coils. They are mainly used in making constructional roofing and walling, appliances, kitchenware, furniture, transportation vehicle materials, and interior decoration materials, etc.
Electrical steel coils are made by using extra low carbon and low nitrogen cold-rolled steel as the base metal, which is firstly tempered to possess a specific magnetic property by applying a special hot rolling process, a cold reduction process and an annealing cycle, and then degreased with hot caustic and flushed with the DW water, and finally coated with an insulating film. Presently the available sizes are 0.50 mm in thickness and 1,000～1,200 mm in width; other sizes are subject to negotiation.
The insulating coating on CSC’s electrical steel coils possesses the functions of insulation, heat resistance, corrosion resistance, coolant media resistance, collision resistance and weldability, and the coils possess the features of low iron loss, high magnetic density and low magnetic aging. CSC produces four grades of electrical steel coils according to their magnetic properties: 50A1300, 50A1000, 50A800 and 50A600 and two kinds of coatings according to the insulating films applied, namely, the general hybrid coating film (C607) and the anneal resistant hybrid coating film (C627, C628). The main applications are in manufacturing motor cores, transformers, stabilizers, relays and cores of electric panels.
The production capacity is 325,000 tons per year, and the available sizes are 0.3~1.6mm in thickness, 850 ~ 1670mm in width, with the maximum coil weight of 30 tons, the maximum outer diameter of 2250mm, and the inner diameters of 508mm and 610mm.
Both CSC's electro-galvanized steel products and cold rolled products possess the similar mechanical property and workability; the former are better than the latter in corrosion resistance. Generally, the zinc- coated weight is 10~30g/m2 with the aim of 20g/m2. CSC's electro-galvanized steel products are surface treated in different ways to match the need of diverse applications.
1. P：Zinc-coated steel＋Phosphate coating treatment. This product is generally used as a base metal for baked painting.
2. C：Zinc-coated steel＋Chromate coating treatment. This product is generally used as a base metal to produce laminated steel.
3. AFP：Zinc-coated steel＋Chromate coating treatment＋Anti-finger print. This product is widely used in manufacturing computer cases, furniture, appliances, and drawing parts.
4. L：Zinc-coated steel＋Chromate coating treatment＋Pre-lubricant coating treatment. This product is typically applied in motor case manufacturing.
China Steel has the only Continuous Galvanizing Line (CGL) that produces both Zn-coated steel coils (referred to as GI) and Zn-Fe coated steel coils (referred to as GA) in Taiwan. The production capacity of the CGL is 300,000 tons per year, and its available sizes are 0.3~2.4mm in thickness, 850 ~ 1676mm in width, with the maximum coil weight of 22 tons, the maximum outer diameter of 1980 mm, and the inner diameters of 508 mm and 610 mm. The Line is characterized by
1. The zinc tank is operated with the unleaded zinc bath to respond to the demand of environmental protection. Because it is designed with a mass volume (230 tons), the temperature and the chemical composition of the zinc bath can be controlled steadily.
2. With the most innovative Roll-Coating equipment, post treatment can be done with different mixes of chemical reagents at the customers' requests, and this can also meet the demand of environmental protection in waste reduction.
Generally, GI is not galvannealed and is mainly used in applications such as a base metal for making color steels, constructional materials, computer cases, furniture, slip rails, wind tubes, etc. GA is galvannealed after the process of Zinc Pot Galvanizing is finished, and can be made into general structural steel, or high strength steel. It can also be made to possess the property for deep drawing use and can also be applied in making the "bake-harden" type of products depending on the customers' working or forming demands. It is mainly used in manufacturing car bodies and appliance parts, etc. The thickness of the zinc coating, which can be made according to the customers' requests, together with the suitable chemical treatment (e.g. chromate coating treatment, or anti-finger print treatment), enables CSC's hot-dip galvanized and galvannealed steel coils to become truly diversified products with excellent quality.
