Manufacturing technique of 150-300mm thick low-alloy high-strength steel plate

Abstract

The invention discloses a manufacturing technique of a 150-300mm thick low-alloy high-strength steel plate. The chemical components of the used continuous casting slabs are as follows: 0.14-0.20% of C, 0.20-0.50% of Si, 1.10-1.60% of Mn, equal to or less than 0.010% of S and equal to or less than 0.20% of micro-alloyed elements; and at least two continuous casting slabs are provided with grooves, overlapped and welded into a big-thickness continuous casting blank by using a combined welding technique of gas shielded welding, submerged-arc welding and electron-bombardment welding, and then, the blank is arranged in a bogie-type furnace or a soaking pit furnace for heating, rolled by a thick plate rolling machine after being discharged from the furnace, cooled under control and subjected to heat treatment so as to obtain the steel plate. The produced low-alloy high-strength steel plate has the following characteristics that the comprehensive mechanical properties are excellent, the inspection qualified rate is higher than 98%, the Q345E level steel plate low-temperature (-40) DEG C impact absorbing energy is more than 160J averagely, the Z-direction tensile section shrinkage factor is more than 60%, and the blank yield is higher than 88%.

Description

technical field [0001] The invention belongs to the field of metal materials, and relates to a manufacturing method for producing low-alloy high-strength steel plates with a thickness of 150 to 300 mm by using ordinary continuous casting slabs. Background technique [0002] 150-300mm low-alloy high-strength steel plates are widely used in national economic fields such as heavy machinery manufacturing, high-rise buildings, bridges, and electric power. The product requires high strength, good ductility and internal quality. Restricted by the thickness of the continuous casting billet, domestic production of extra-thick steel plates with guaranteed flaw detection and performance protection by continuous casting billets is generally up to 150 mm thick, and steel plates above 150 mm generally adopt die-casting steel ingots, electroslag ingots, etc., and the production process has low yields. High energy consumption, low production efficiency and other shortcomings. Contents of...

AI Technical Summary

Problems solved by technology

Restricted by the thickness of the continuous casting billet, domestic production of extra-thick steel plates with guaranteed flaw detection and performance protection by continuous casting billets is generally up to 150 mm thick, and steel plates above 150 mm generally adopt die-casting steel ingots, electroslag ingots, etc., and the production process has low yields. Disadvantages such as high energy consumption and low production efficiency

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