钇基稀土微合金化E36船板钢相变规律及组织性能研究
发布时间：2019-01-01 07:42
【摘要】：船舶工业的快速发展,对船舶用钢提出了更高的要求。目前高品质船舶用钢的制造主要是通过Nb、Ti等元素的微合金化作用并结合TMCP轧制技术。近年来随着钢洁净度的提高,稀土在钢中的应用越来越受到重视。大量的研究表明,轻稀土元素可以改善钢的组织并且提高钢材的综合性能。本文以E36船板钢为研究对象,通过喂线的方式在E36船板钢的精炼过程中喂入钇基稀土包芯线,研究钇基稀土对E36船板钢组织性能及相变规律的影响。具体研究内容和结论如下:(1)钇基稀土对E36钢相变规律的影响主要有:(1)添加钇基稀土以后,E36钢的AC1和AC3分别由710℃、875℃提高到730℃、885℃;(2)E36RE钢在组织中的贝氏体量有所减少;(3)E36RE钢在不同冷却速度下组织的硬度有所降低;(4)E36RE钢CCT曲线较E36钢有所左移,贝氏体的转变温度有所提高。(2)添加钇基稀土后,E36RE钢较E36钢珠光体量有所增加,且游离渗碳体较弥散;并且E36R钢较E36钢珠光体片层间距缩小,且珠光体表现为退化态。稀土元素在晶界等缺陷处偏聚和过冷度增加是珠光体增加的主要原因。添加钇基稀土后,钢液过冷度增加和稀土元素在钢中的固溶,阻碍了C原子的扩散迁移,从而限制了渗碳体的形核速度与长大速度,细化了珠光体组织。(3)钇基稀土E36钢中的夹杂物由变质作用。一方面是对夹杂物形态的变质,添加稀土前,钢中的夹杂物主要是CaO、Al2O3等金属夹杂物和MnS夹杂物,添加钇基稀土后,钢中夹杂物变质为稀土复合夹杂物。另一方面是改善了夹杂物的尺寸,添加稀土前E36钢横向夹杂物主要为20微米左右的长条状MnS夹杂物,添加稀土以后,E36RE钢中夹杂物主要为小于5μm以内的球状稀土复合夹杂物。(4)钇基稀土对E36钢的冲击性能有明显的改善,主要体现在:(1)对冲击韧性有良好的改善,尤其是低温冲击韧性。(2)减小了纵向和横向冲击功值的差异,降低了冲击功的纵横比,改善了各向异性。组织的细化及夹杂物的改性是影响冲击性能的主要原因。
[Abstract]:With the rapid development of ship industry, higher requirements are put forward for ship steel. At present, the manufacture of high quality marine steel is mainly through the microalloying of elements such as Nb,Ti and TMCP rolling technology. In recent years, with the improvement of steel cleanliness, the application of rare earth in steel has been paid more and more attention. A large number of studies have shown that light rare earth elements can improve the structure of steel and improve the comprehensive properties of steel. In this paper, the yttrium base rare earth cored wire was fed to E36 ship plate steel in the process of refining by feeding wire to study the effect of yttrium base rare earth elements on the microstructure and phase transformation of E36 ship plate steel. The specific research contents and conclusions are as follows: (1) the effects of yttrium base rare earth on the transformation of E36 steel are as follows: (1) after adding yttrium base rare earth, the AC1 and AC3 of E36 steel increase from 710 鈩，
本文编号：2397215
[Abstract]:With the rapid development of ship industry, higher requirements are put forward for ship steel. At present, the manufacture of high quality marine steel is mainly through the microalloying of elements such as Nb,Ti and TMCP rolling technology. In recent years, with the improvement of steel cleanliness, the application of rare earth in steel has been paid more and more attention. A large number of studies have shown that light rare earth elements can improve the structure of steel and improve the comprehensive properties of steel. In this paper, the yttrium base rare earth cored wire was fed to E36 ship plate steel in the process of refining by feeding wire to study the effect of yttrium base rare earth elements on the microstructure and phase transformation of E36 ship plate steel. The specific research contents and conclusions are as follows: (1) the effects of yttrium base rare earth on the transformation of E36 steel are as follows: (1) after adding yttrium base rare earth, the AC1 and AC3 of E36 steel increase from 710 鈩，
本文编号：2397215
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