钇基稀土对E36钢板显微组织及冲击性能的影响

运用扫描电镜及能谱等分析手段研究了钇基稀土对E36钢中夹杂物的变质作用以及对显微组织和冲击性能的影响.研究表明,钇基稀土改善了E36钢的显微组织,减少了珠光体的片间距和含量.加入钇基稀土后,E36钢的冲击断口由典型的解理断口变为准解理+韧窝型断口,韧窝中细小球状的稀土夹杂是其转变的主要原因.加入少量的钇基稀土显著改善了E36钢的冲击韧性,尤其是低温冲击性能.在-60℃情况下,E36Re钢的纵向冲击功较E36钢提高了33.5%,横向冲击功提高了113.7%.并且,钇基稀土显著改善了E36钢纵横向冲击性能的差异性,未加稀土E36钢的纵、横冲击比均大于1.70,-60℃条件下达到2.77,而E36Re钢的纵、横冲击比为1.51~1.73.

Effect of Y-base rare earth on the microstructure and impact toughness of E36 steel plate

The effect of Y-base rare earth on the inclusions modification, microstructure and impact toughness of E36 steel was in-vestigated by using scanning electron microscopy and energy spectrum analysis. The results indicate that Y-base rare earth improves the microstructure and reduces the interlamellar spacing and content of pearlite. The typical cleavage fracture of E36 steel is quasi-cleavage and dimple fracture when adding Y-base rare earth. Fine and spherical rare earth inclusions are the main reason for the frac-ture transformation. The impact toughness of E36 steel is improved obviously by Y-base rare earth, especially at the low temperature. In comparison with E36 steel without Y-base rare earth, the longitudinal impact energy of E36 steel containing Y-base rare earth is in-creased by 33. 5%, and the transverse impact energy is increased by 113. 7% at -60℃. Moreover, the difference of longitudinal and transverse impact toughness is decreased by Y-base rare earth significantly. To E36 steel without Y-base rare earth, the proportion of longitudinal and transverse impact values is greater than 1. 70 and it reaches 2. 77 at -60℃. And the proportion of longitudinal and transverse impact values is 1. 51-1. 73 for E36 steel plate containing Y-base rare earth.