微合金元素钒和铌对诱发针状铁素体的影响

 氧化物冶金是将非金属夹杂物变害为利，它是利用钢中高熔点粒子改善钢的组织，进而改善钢板焊接热影响区（HAZ）性能的有效手段。以DH36级船板钢为依托钢种，根据二维错配度理论，系统研究了不同微合金元素铌和钒对船板钢铸态组织中诱发奥氏体晶内针状铁素体(IAF)的影响。研究表明，根据错配度理论，微合金元素钒易于铌诱发IAF，但是当奥氏体向铁素体转变时，微合金元素钒的第二相粒子在钢中析出温度低、析出量少，所以微合金元素铌充分细化了钢的铸态组织、轧态及焊接HAZ组织，HAZ低温冲击韧性约为微合金元素钒的4倍，达到工业化生产大线能量焊接用钢板的要求。

Effect of microalloy elements V and Nb on induction of #br# intragranular acicular ferrite

Oxide metallurgy, as a domain research in recent years on how to take the most advantage of the non metal inclusions, is one of the effective methods to refine the microstructure of steel by using high melting particles, and then to refine the welding performance in HAZ in steel plate. Relied on DH36 shipbuilding steel, guided by the two dimensional disregistry method, on the basis of the laboratory test of the composite microalloying Nb and V, different impacts in inducing intragranular acicular ferrite in the ingots microstructure of the shipbuilding steel had been systematic researched, it showed based on the two dimensional disregistry method, the carbonitride in the microalloy V in the steel was much easier to induce IAF nucleation than that in the Nb. But the precipitation temperature of the carbonitride in the microalloy V was lower while the quantity of the carbonitride in the Nb was higher than that in the V. Therefore microalloy element Nb can optimize the casting state structure effectively and improve the welding toughness of HAZ, and the low temperature performance was 4 times than V. The results were of great significance to the modification and improvement of the existing theory of oxide metallurgy.