Low-cost continuous casting billet produced large-thickness steel plate for low-temperature pressure vessel and production method thereof

Abstract

The invention discloses a low-cost continuous casting billet produced large-thickness steel plate for low-temperature pressure vessel and a production method thereof. The steel plate comprises the following chemical components in percentage by mass: 0.05-0.10% of C, 0.20-0.50% of Si, 1.30-1.60% of Mn, less than or equal to 0.012% of P, less than or equal to 0.005% of S, 0.020-0.050% of Alt, less than or equal to 0.70% of Ni, less than or equal to 0.040% of Nb, and the balance of Fe and inevitable impurities. The production method specifically comprises the procedures of smelting, casting, heating, rolling, and heat treatment. According to the present invention, with reasonable composition design and the production process of controlled rolling and controlled cooling, and heat treatment, and by completely using continuous casting billets for production, the maximum thickness of the steel plate reaches up to 120 mm; the produced steel plate has favorable comprehensive mechanical properties and welding properties, and is low in production cost and high in market competitiveness, thus meeting the increasing market demand.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to steel plates for low-cost continuous casting slabs and large-thickness low-temperature pressure vessels and a production method. Background technique [0002] At present, steel plates for low-temperature pressure vessels such as Q345R, 16MnDR, 12MnNiVR, 15MnNiDR, 15MnNiNbDR, SA203E (08Ni3DR, 3.5Ni), SA516Gr70, and 07Mn series are widely used in the manufacture of low-temperature pressure vessels. In particular, 09MnNiDR steel plate is used as low-alloy structural steel for low-cost continuous casting slabs and large-thickness low-temperature pressure vessels. Because this type of steel plate has the characteristics of high purity, high toughness, high internal quality, and high technical requirements, it is mainly used in petroleum and chemical industries. Equipment deethanizer, CO2 absorption tower, medium pressure flash tower, cooler, deethanizer, reabsorption to...

AI Technical Summary

Problems solved by technology

These two patents require that the thickness of the steel plate is less than 60mm to be produced by continuous casting, and the thickness of the steel plate is ≥60mm to be produced by die casting. cycle

At the same time, in the heat treatment process, the two patents have formulated different and more complex heat treatment processes. The tempering process in each heat treatment process is also different. The process is very cumbersome and complicated. In actual production execution, the furnace needs to be constantly adjusted. parameters, which is not conducive to the stable execution of the process

In particular, the Patent Publication No. 104911319A requires the continuous casting superheat to be in the range of 30-50°C. If the superheat is high, the smelting cost and time will be consumed in the smelting process, and the latent heat of solidification is large, which is not good for flaw detection and performance.

In addition, in the heat treatment process of this patent, for steel plates with a thickness of 8 mm to 120 mm, the thickness is divided into four ranges, and four different heat treatment processes are formulated respectively. There are many heat treatment systems, and it can be seen that the thickness has a great influence on the heat treatment process. Slow down the pace of production, which is not conducive to the smooth progress of production

Images