Control method for coast atmospheric corrosion resistant scale on surface of boat deck

Abstract

The invention discloses a control method for coast atmospheric corrosion resistant scale on the surface of a boat deck, which belongs to the field of steel for hull structures. According to the invention, the structure and thickness of scale on the surface of a boat deck is controlled by optimizing production processes for boat decks. The method comprises the following key points: controlling parameters of heating temperature, time, residual oxygen and the like for continuous casting billets and reinforcing a de-scaling effect once; controlling the index of chloride ion in water for production, reducing the content of deposited chloride ions in scale and inhibiting corrosive pitting; controlling initial rolling temperature and finishing rolling temperature in the stage of finish rolling, reasonably utilizing a weak water cooling system, increasing the content of Fe3O4 in scale, reducing the content of Fe2O3, retaining a small amount of FeO and enabling the scale to have good plasticity, a bonding force and corrosion resistance. The advantages of the invention are as follows: it does not need to reconstruct existing equipment, and the surface quality and production efficiency of the boat deck can be enhanced through technological optimization; structural composition of the scale is reasonably controlled, which enables the surface of the boat deck to have excellent coast atmospheric corrosion resistance, especially enables corrosive pitting caused by chloride ions to be inhibited, and enables the storage duration of the boat deck in coast environment to be prolonged.

Description

technical field [0001] The invention belongs to the technical field of steel for hot-rolled flat hull structures, and in particular relates to a control method for ship plate surface resistant to coastal atmospheric corrosion oxide scale, which is suitable for general-strength and high-strength (32kg, 36kg) ship plates. Background technique [0002] Ship plate is one of the important varieties of wide and thick plate. Since the fourth quarter of 2008, due to the impact of the global financial crisis on the world economy, steel and downstream industries have been greatly impacted, mainly manifested in the reduction of infrastructure investment, a sharp drop in steel demand, and a sharp drop in steel product orders. As a result, shipyards generally encounter shipowners' request to delay delivery, slow down production pace, substantial increase in ship plate inventory and prolonged inventory cycle. Since the beginning of 2009, the number of users' objections to the quality of ...

AI Technical Summary

Problems solved by technology

Because the defect is obvious and widely distributed on the surface of the steel plate, the surface condition is unqualified, and it can be used only after manual grinding or repair welding, and even deep pits often appear locally. The scrapping of a steel plate will cause great economic losses to both the steel mill and the shipyard.

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