AS NZS 3678-350L15Z15-Z35 controlled rolling structure steel plate having thickness of 50-80 mm and manufacturing method thereof

Abstract

The invention relates to an AS NZS 3678-350L15Z15-Z35 controlled rolling state structure steel plate having thickness of 50-80 mm. Chemical composition adopts Fe as a basic element and contains elements as follows: 0.12%-0.16% of C, 0.10%-0.50% of Si, 1.30%-1.60% of Mn, smaller than or equal to 0.015% of P, smaller than or equal to 0.005% of S, smaller than or equal to 0.20% of Cr, smaller than orequal to 0.08% of Mo, 0.10%-0.25% of Ni, smaller than or equal to 0.30% of Cu, 0.02%-0.04% of Al, smaller than or equal to 0.02% of V, 0.02%-0.055% of Nb, 0.01%-0.025% of Ti, smaller than or equal to0.008% of N and inevitable impurity elements. A continuous casting is taken as a blank and subjected to controlled rolling, straightening and other steps, and a final product with controlled rolling(CR) state as the delivery state is obtained. The production process comprises the steps as follows: pretreatment of hot metal, converter smelting, LF (ladle furnace) refining, RH furnace refining, blank casting by a continuous casting machine, blank heating, controlled rolling, cooling and finishing, and by means of the process, the AS / NZS 3678-350L15(Z15-Z35) controlled rolling structure steel plate with the thickness larger than 50-80 mm and CR as the delivery state can be produced.

Description

technical field [0001] The invention relates to Z15-Z35 structural steel, in particular to a series of AS / NZS 3678-350 structural steel. Background technique [0002] Z-direction steel is a common name for steel plates with properties in the thickness direction, and there are special regulations on the mechanical properties in the thickness direction of thicker steel plates. In the structural steel connected by welding, when the thickness of the steel plate is not less than 15mm and bears the tensile force along the thickness direction of the plate, in order to avoid lamellar tearing during welding, it is necessary to use steel that resists lamellar tearing (usually referred to as "Z-direction"). steel"). Thick plates have the problem of lamellar tearing, so a Z-direction performance test is proposed. This kind of steel plate is a steel that has been specially smelted and treated on the basis of a certain level of structural steel (called parent steel). . The mechanical ...

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Problems solved by technology

This method has a long production period, high production cost, and the delivery status is normalizing

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