What are the technical requirements for carbon structural steel hot-rolled strips?
by：Hongmei
2021-03-15
The technical conditions of hot-rolled steel strip products of carbon structural steel with a width of 50-300mm and a thickness of 2-6mm should meet the requirements of the GB3524-92 standard. The mechanical properties and chemical composition of the produced steel strip should meet the requirements of GB700-88 'Carbon Structural Steel'. The steel strip should be folded flat or rolled into a straight strip for delivery.
The size and surface of the steel strip should meet the following requirements:
(1) The allowable deviation of the thickness and width of the steel strip shall meet the requirements of Table 4-1.
(2) The thickness of the steel strip should be uniform. Measure the thickness at three points in the middle and both sides of the same section, and the maximum difference (three point difference) should meet the requirements of Table 4-2. The sickle bend of the steel belt is not more than 6mm per meter, and the total sickle bend is not more than 0.6% of the total length. The thickness of the steel strip used as the cold-rolled billet along the rolling direction should be uniform. The thickness of two points on the same straight line should be measured at random, and the maximum difference (the same deviation) should be:
steel strip width ≤150mm, the same strip difference is not more than 0.20mm
＞150mm The same strip difference is not more than 0.25mm
(3) The length of the steel strip with a thickness of 2.0-4.0mm shall not be less than 6m. It is allowed to deliver steel strips with a length of not less than 4m, but the quantity shall not exceed 8% of the total mass of the batch. The length of the steel strip with a thickness greater than 4.0-6.0mm shall not be less than 4m. It is allowed to deliver steel strips with a length of not less than 3m, but the quantity shall not exceed 8% of the total mass of the batch.
(4) The surface of the steel strip should be smooth and clean, free of cracks, folds, delamination, pores, non-metallic inclusions, coarse burrs and scales, and depth or height not greater than half of the allowable deviation of the thickness (height refers to the positive deviation) , Depth refers to negative deviation) Locally small pits, scratches, pits, bumps and erythema with a depth not greater than 0.08mm. Surface and side defects of the steel strip are allowed to be removed, and the removal depth of the same section shall not exceed the allowable negative deviation of thickness and width. There shall be no cracked edges on the side of the steel belt, slight burrs are allowed, and the depth shall not be greater than 1/5 of the allowable negative deviation of the width.
The size and surface of the steel strip should meet the following requirements:
(1) The allowable deviation of the thickness and width of the steel strip shall meet the requirements of Table 4-1.
(2) The thickness of the steel strip should be uniform. Measure the thickness at three points in the middle and both sides of the same section, and the maximum difference (three point difference) should meet the requirements of Table 4-2. The sickle bend of the steel belt is not more than 6mm per meter, and the total sickle bend is not more than 0.6% of the total length. The thickness of the steel strip used as the cold-rolled billet along the rolling direction should be uniform. The thickness of two points on the same straight line should be measured at random, and the maximum difference (the same deviation) should be:
steel strip width ≤150mm, the same strip difference is not more than 0.20mm
＞150mm The same strip difference is not more than 0.25mm
(3) The length of the steel strip with a thickness of 2.0-4.0mm shall not be less than 6m. It is allowed to deliver steel strips with a length of not less than 4m, but the quantity shall not exceed 8% of the total mass of the batch. The length of the steel strip with a thickness greater than 4.0-6.0mm shall not be less than 4m. It is allowed to deliver steel strips with a length of not less than 3m, but the quantity shall not exceed 8% of the total mass of the batch.
(4) The surface of the steel strip should be smooth and clean, free of cracks, folds, delamination, pores, non-metallic inclusions, coarse burrs and scales, and depth or height not greater than half of the allowable deviation of the thickness (height refers to the positive deviation) , Depth refers to negative deviation) Locally small pits, scratches, pits, bumps and erythema with a depth not greater than 0.08mm. Surface and side defects of the steel strip are allowed to be removed, and the removal depth of the same section shall not exceed the allowable negative deviation of thickness and width. There shall be no cracked edges on the side of the steel belt, slight burrs are allowed, and the depth shall not be greater than 1/5 of the allowable negative deviation of the width.
