EASY-TO-WELD STEEL PLATE WITH EXCELLENT LAMELLAR TEARING RESISTANCE AT LOW TEMPERATURE AND PREPARATION METHOD THEREFOR

摘要

Provided is an easy-to-weld steel plate with excellent lamellar tearing resistance at low temperature. The steel plate comprises the following chemical components in percentages by mass: C: 0.05-0.09%; Si: 0.2-0.4%; Mn: 0.9-1.3%; Al: 0.02-0.04%; Nb: 0.01-0.03%; V: 0.03-0.05%; Cr: 0.3-0.5%; Ni: 1.0-1.4%; Mo: 0.3-0.6%; Cu: 0.2-0.6%; Ti: 0.01-0.02%; B: 0.001-0.002%; P: ≤0.015%; S: ≤0.003%; N: ≤0.007%; and the balance Fe and inevitable impurities. The carbon equivalent is less than or equal to 0.60, and the welding crack sensitivity coefficient Pcm is less than or equal to 0.28. By the process steps of KR hot metal pretreatment, converter smelting, LF refining, RH vacuum degassing, continuous casting, rolling, straightening, steel plate stack slow cooling, quench tempering and the like, high-strength, high-toughness and easy-to-weld steel plates with the thicknesses ranging from 70 mm to 100 mm are prepared.