变形量对铝硅镀层热冲压用钢组织和性能的影响

Effect of deformation on microstructure and mechanical properties of aluminum-silicon coating hot stamping steel

研究了不同轧制变形量条件下铝硅镀层热冲压用钢在热冲压淬火处理前后组织和力学性能的转变规律。结果表明,随着变形量的增加,试验钢镀层厚度逐渐减少,合金层发生破碎且程度逐渐加大,Al-Si镀层与基体接触面积增大。相同条件下热冲压淬火处理后,随着变形量的增加,镀层厚度逐渐减少,合金层重新连续分布于镀层和基板之间,且合金层厚度增加,基板中发现粗大的马氏体组织。未热处理试验钢拉伸强度、维氏硬度随着变形量增加而逐渐增加,但伸长率急剧减少,热冲压淬火处理后不同厚度试验钢均实现1500 MPa高强化,断裂伸长率随着变形量增加呈现逐渐降低的趋势。

Changes of microstructure and mechanical properties of aluminum-silicon coating hot stamping steel before and after hot stamping quenching were studied under different rolling deformation conditions.The results indicate that with the increase of deformation,the coating layer thickness of the tested steel decreases gradually,and the alloy layer is broken and the broken degree increases gradually.The contact area between Al-Si coating layer and matrix increases.After the same hot stamping and quenching treatment and with the increase of deformation,the thickness of the coating layer still decreases,the alloy layer redistributes continuously between the coating layer and the substrate,the layer thickness is increased,and coarse martensite structures are found in the substrate.The tensile strength and Vickers hardness of the untreated tested steel increase gradually with the increase of deformation,but the elongation decreases sharply.The tested steel with different thickness after hot stamping and quenching can all be strengthened to a high strength as 1500 MPa,while the elongation decreases gradually with the increase of deformation.