Specs : Cold rolled steel coil

Product Introduction

A cold rolled steel sheet is produced by pickling a hot coil and rolling it uniformly at an appropriated temperature to a thinner thickness. It has excellent surface configuration and superb mechanical properties for use in automobile and electronic appliance production.

Manufacturing availability

Quality Specifications Classification KSD 3512 JIS G3141 ASTM A1008 EN10130 CQ (Commercial Quality) SPCC SPCC CS DC01(Fe P01) DQ (Drawing Quality) SPCD SPCD DS DC03(Fe P03) DDQ (Deep Drawing Quality) SPCE SPCE DDS DC04(Fe P04) DDQ-N (StabilizedDeep Drawing Quality) SPCEN SPCEN DDS DC04(Fe P04) EDDQ     EDDS DC05(Fe P05)   Classification of Products     Commercial Sheet of this quality is for simple bending or moderate forming.  Commercial steel sheet can be bent flat upon itself 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.     Drawing Sheet of this quality has a greater degree of ductility and is more consistent in performance than commercial steel because of higher standards in production, selection and melting of the steel. It is suitable for automotive panels, audio-visual equipment, and heating apparatuses.     Deep Drawing Sheet of this designation should be used when drawing steel will not provide a sufficient degree of ductility for fabrication of parts with stringent 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 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 straining.   Surface Finish The surface finish of cold-rolled steel sheet is either dull or bright.   Dull Finish Dull finish, which is attained by attaching numerous fine grains onto the steel surface, is often called 'pear-skin finish' or 'egg-shell texture'. The grains are made by steel grit blasted roll.  The dull finish is useful in drawing because lubricant oil can be evenly spread over the entire surface, thereby reducing the possibility of friction.  The fine grains also help boost paint adherence and extend the steel life span of the steel.     Bright Finish Bright finish presents high-quality roughness that is optimal for decorative purposes. The sheet surface is rolled with fine polished rolls.   Edges Classification Specifications Mill Edge Edges produced by trimming hot rolled coil during the pickling process, prior to cold rolling. Slit Edge (Trimmed Edge) Edges produced by shearing or slitting during the cold rolling process.   Oiling Sheet that is processed with the final step being the application of oil to the surface; usually intended to provide protection from rusting during shipment and storage. The oil may also serve to assist in the subsequent fabrication process, but this is not usually the main purpose. Dongbu Steel delivers its steel products either oiled (heavy, general or light, dos oiling, powdering) or un-oiled.

Testing Methods

Testing Methods Tensile testing is performed to determine the yield strength, tensile strength, and elongation of steel sheet. Test Specimen All types and sizes of test pieces for tension testing are prescribed in the Specifications of KS, JIS, and ASTM. Cold rolled steel sheet, for example, generally uses the specimen collection method indicated in KS B0801. NO.5 Results Tension test results are used as a basis for determining the workability and formability of steel sheet. a : Elongation Greater elongation provides increased workability. b : Yield Point A lower yield point gives better shape to the end product. c : Yield Ratio (yield point/tensile strength) A lower yield ratio indicates widened differentiation between tensile strength and yield point. Greater difference translates into better workability. d : d. Modulus of Elasticity The modulus of elasticity is in an inverse relationship with resistance to elastic strain. Lowered resistance indicates a better formed product. e : n-Value (Modulus of Work Hardening) This measure is yielded when the stress- strain curve approximates ∂=CE". Workability is proportionate to the n-value. f : r-Value (Modulus of Plastic Deformation) Surface shrinkage in the direction of thickness has an inverse relationship with the r-value and the shrinkage in the direction of width is directly proportionate to the r-value. The higher the value, the less susceptible to fracture, hence better drawability.   Bending Test The bending test is performed to determine the ductility of steel sheet. The test specimen for cold-rolled steel sheet is designated in KS B 0801 No.3. In the test, the specimen is bent to a specified angle on a mandrel or a specified radius until fracture. The ductility of the sheet is judged by the cracks on the outside of the bent specimen. A cold-rolled sheet specimen is bent 180 degrees.   Hardness Test Hardness of steel sheet is closely related to other properties like strength, wear resistance, and workability. The hardness test is an easy and effective method of identifying various properties of steel sheet. The Rockwell Hardness test is used for measuring the hardness of cold-rolled steel sheet. The test method is described as follows. Rockwell Hardness Test Material resistance to indentation is a qualitative indication of its strength. A steel ball or diamond is often used as an indenter. The hardness value is determined by the difference in penetration depth from the application of an initial minor load onto the indenter followed by a major load. The process is repeated twice. The penetration depth on the surface depends on the increase level in pure load, namely, the B-scale and the F-scale. The B-scale uses a 1/16 (1.588 mm) steel ball indenter and the major load is 100kg. The B-scale most accurately measures specimens with the thickness of 0.762mm (0.030 in.) or over. It is preferable to use the F-scale for specimens with a thickness under 0.762mm.   Workability Test Tensile strength of cold-rolled steel sheet can be measured in various ways. Since tensile strength is developed through a complicated production process, it is difficult to measure the strength. The two most common ways to measure strength are: Erichsen Test This test measures the drawability of steel sheet. As is shown in the diagram, a test specimen is punched down with a steel ball plunger until the test piece cracks. The h- value, measured when the fracture occurs, is the Erichsen value. Conical Cup Test This method has gained popularity in recent years. The specimen is pressed with a flat or round puncher as shown in the diagram. The test value is obtained by measuring the diameter of the cup that the specimen has been drawn into. Because the value closely corresponds to the actual performance of steel sheet fabrication, this test method is widely used by automobile makers.

Measurement Range

Note: 1. Sizes indicated in  will be subjected to negotiation. 2. Coil is available with an inside diameter of 508㎜(20in.) or 610㎜(24in.) 3. Coil is available in weight ranging between 2.5 tons (5,500 lbs.) are 20 tons (44,000 lbs.)

Comparison of Standards

Chemical Components Standard Specification Applications Chemical Component C Si Mn P S KS D 3512 (JIS G 3141) SPCC CQ ≤ 0.12 - ≤ 0.50 ≤ 0.040 ≤ 0.045 SPCD DQ ≤ 0.10 - ≤ 0.45 ≤ 0.035 ≤ 0.035 SPCE (N) DDQ (Non-Aging) ≤ 0.08 - ≤ 0.40 ≤ 0.030 ≤ 0.030 ASTM A 1008 CS CQ ≤ 0.10 - ≤ 0.60 ≤ 0.030 ≤ 0.035 DS DQ ≤ 0.08 - ≤ 0.50 ≤ 0.020 ≤ 0.030 DDS DDQ (Non-Aging) ≤ 0.06 - ≤ 0.50 ≤ 0.020 ≤ 0.025 EN 10130 DC01 (Fe P01) CQ ≤ 0.12 - ≤ 0.60 ≤ 0.045 ≤ 0.045 DC03 (Fe P03) DQ ≤ 0.10 - ≤ 0.45 ≤ 0.035 ≤ 0.035 DC04 (Fe P04) DDQ (Non-Aging) ≤ 0.08 - ≤ 0.40 ≤ 0.030 ≤ 0.030 DC05 (Fe P05) EDDQ ≤ 0.06 - ≤ 0.35 ≤ 0.025 ≤ 0.025 Mechanical Properties Standard Specification Application Mechanical Property Y.P T.S Elongation Min (%) Yielding Point (N/㎟) Tensile Strength (N/㎟) 0.25≤t ＜0.40 0.40≤t ＜0.60 0.60≤t ＜1.0 1.0≤t ＜1.6 1.6≤t ＜2.5 t≥2.5 KS D 3512 (JIS G 3141) SPCC CQ - ≥270 (32) (34) (36) (37) (38) (39) SPCD DQ - ≥270 34 36 38 39 40 41 SPCE (N) DDQ (Non-Aging) - ≥270 36 38 40 41 42 43 ASTM A 1008 CS CQ (140~275) - 30 (L0 =50mm) 　 DS DQ (150~240) -  36 (L0 =50mm) 　 DDS DDQ (Non-Aging) (115~200) -  38 (L0 =50mm) 　 EDDS EDDQ (105~170) -  40 (L0 =50mm) EN 10130 DC01 (Fe P01) CQ ≤ 280 270~410 28 (L0 =80mm) 　 DC03 (Fe P03) DQ ≤ 240 270~410  34 (L0 =80mm) 　 DC04 (Fe P04) DDQ (Non-Aging) ≤ 210 270~410  38 (L0 =80mm) 　 DC05 (Fe P05) EDDQ ≤ 180 270~410  40 (L0 =80mm)     Standard Specification Mechanical Property Hardness Temper HRB Hv KS D 3512 (JIS G 3141) 1/8H 50~71 95~130 1/4H 65~80 115~150 1/2H 74~89 135~185 H ≥85 ≥170

Standard Packing

Dongbu Steel’s cold-rolled sheet and coil is packed to withstand handling during transportation and long-distance shipping. Special care is taken to prevent abrasion, rusting and scratching. Our packing procedure is illustrated below. The unit weight per package is usually between 2 and 5 tons for sheet and between 4 and 20 tons for coil. Coil Packing Sheet Packing

Sheet Weight Table

Weight Weight per Sheet Classification Thickness Width 3ft (914mm) 3.28ft (1,000mm) 4ft (1,219mm) 5ft (1,524mm) Length 6ft (1,829mm) 6,56ft (2,000mm) 8ft (2,438mm) 10ft (3,048mm) Weight Unit in. mm lb/ft² kg/㎡ lb kg lb kg lb kg lb kg * 0.0079 0.20 0.3226 1.570 5.81 2.63 6.94 3.14 10.3 4.67 16.1 7.29 0.0091 0.23 0.3716 1.806 6.69 3.02 8.00 3.61 11.9 5.37 18.6 8.39 * 0.0098 0.25 0.4002 1.962 7.20 3.28 8.61 3.92 12.8 5.83 20.0 9.11 * 0.0106 0.27 0.4329 2.120 7.79 3.54 9.31 4.24 13.9 6.30 21.6 9.85 * 0.0118 0.30 0.4819 2.355 8.67 3.94 10.4 4.71 15.4 7.00 24.1 10.9 0.0130 0.33 0.5309 2.590 9.56 4.33 11.4 5.18 17.0 7.70 26.5 12.0 * 0.0138 0.35 0.5636 2.748 10.1 4.59 12.1 5.50 18.0 8.17 28.2 12.8 * 0.0157 0.40 0.6412 3.140 11.5 5.25 13.8 6.28 20.5 9.33 32.1 14.6 * 0.0177 0.45 0.7229 3.532 12.0 5.91 15.6 7.06 23.1 10.5 36.1 16.4 * 0.0197 0.50 0.8045 3.925 14.5 6.56 17.3 7.85 25.7 11.7 40.2 18.2 * 0.0217 0.55 0.8862 4.318 16.0 7.22 19.1 8.64 28.4 12.8 44.3 20.1 * 0.0236 0.60 0.9638 4.710 17.3 7.88 20.7 9.42 30.8 14.0 48.2 21.9 * 0.0276 0.70 1.127 5.495 20.3 9.19 24.2 11.0 36.1 16.3 56.4 25.5 * 0.0315 0.80 1.287 6.280 23.2 10.5 27.7 12.6 41.2 18.7 64.4 29.2 * 0.0354 0.90 1.446 7.065 26.0 11.8 31.1 14.1 46.3 21.0 72.3 32.8 * 0.0394 1.00 1.609 7.850 29.0 13.1 34.6 15.7 51.5 23.3 80.5 36.5 0.0433 1.10 1.768 8.635 31.8 14.4 38.0 17.3 56.6 25.7 88.4 40.1 * 0.0472 1.20 1.928 9.420 34.7 15.8 41.5 18.8 61.7 28.0 96.4 43.8 0.0512 1.30 2.091 10.20 37.6 17.1 45.0 20.4 66.9 30.3 105 47.4 * 0.0551 1.40 2.250 10.99 40.5 18.4 48.4 22.0 72.0 32.7 113 51.0 * 0.0591 1.50 2.414 11.78 43.5 19.7 51.9 23.6 77.2 35.0 121 54.7 * 0.0630 1.60 2.573 12.56 46.3 21.0 55.4 25.1 82.3 37.3 129 58.3 * 0.0709 1.80 2.896 14.13 52.1 23.6 62.3 28.3 92.7 42.0 145 65.6 * 0.0787 2.00 3.214 15.70 57.9 26.3 69.2 31.4 103 46.7 161 72.9 * 0.0906 2.30 3.700 18.06 66.6 30.2 79.6 36.1 118 53.7 185 83.9 * 0.1024 2.60 4.182 20.41 75.3 34.1 90.0 40.8 134 60.7 209 94.8 0.1102 2.80 4.501 21.98 81.0 36.8 96.8 44.0 144 65.3 225 102 * 0.1181 3.00 4.823 23.55 86.8 39.4 104 47.1 154 70.0 241 109 * 0.1260 3.20 5.146 25.12 92.6 42.0 111 50.2 165 74.7 257 117 Note: These sizes are applicable to Korea industrial standards.

Width-Weight Curves for Coil

Inside Diameter is 508mm (20 in) * Coil width is the same as that of the cold-rolled strip. * The coil lamination factor is assumed to be 100%.