Low-alloy medium-thickness steel plate Q345D-Z35 and production process thereof

Abstract

The invention discloses a low-alloy medium-thickness steel plate Q345D-Z35 produced without adding microalloy elements and a production process thereof. The steel plate contains the following chemical components in percentage by mass (with wt% as a unit): 0.10 to 0.18 percent of C, 0.20 to 0.45 percent of Si, 1.20 to 1.60 percent of Mn, less than or equal to 0.018 percent of P, less than or equal to 0.005 percent of S, 0.015 to 0.050 percent of Als and the balance of Fe and residual elements. The production method comprises the following steps of: pretreatment with high-quality molten iron or KP molten iron, blowing in a top and bottom combined blown converter, ladle furnace (LF) refining, vacuum degassing treatment, casting blank cooling in pile, treatment in a heating furnace, rolling, ACC (Active Calcium Carbonate) laminar cooling, treatment in a hot straightening machine, cooling in pile, finishing, external inspection, flaw detection and warehousing. The steel plate has the advantages that: compared with the traditional Q345D-Z35, under the conditions that the carbon equivalent is not changed and precious alloys of Nb, Ti and the like are not added, the various performance indexes of the Q345D-Z35 are ensured to meet the national standard requirements, and the production cost is greatly reduced.

Description

technical field [0001] The invention belongs to the field of medium-thick plate production, in particular to a low-alloy Q345D-Z35 medium-thick steel plate produced without adding microalloy elements and a production process thereof. Background technique [0002] The current international financial crisis has caused a great impact on my country's steel enterprises, especially the medium and heavy plate industry of steel mills has been in a downturn. Cost strategy plays a very important role in enhancing the competitiveness of enterprises. At present, there are not many domestic manufacturers of low-alloy Q345D-Z35 medium and thick steel plates, because in the production process, micro-alloying elements such as Nb, V, Ti are added, the production cost is high, and the process is complicated. SUMMARY OF THE INVENTION [0003] In order to cope with the adverse effects of the international financial crisis, realize the low-cost strategy and enhance the competitiveness of enter...

AI Technical Summary

Problems solved by technology

At present, there are not many domestic manufacturers of low-alloy Q345D-Z35 medium-thick steel plates, because in the production process, micro-alloying elements such as Nb, V, and Ti are added, and the production cost is high; the process is complicated

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