钒含量对磨片用7Cr17不锈钢组织及力学性能的影响研究

Study of the Effects of Vanadium Content on the Structure and Mechanical Properties of 7Cr17 Stainless Steel for Refiner Plate

关键词:  7Cr17不锈钢  VC碳化物  微观组织  冲击韧性

Key Words:7Cr17 stainless steel  VC carbide  microstructure  impact toughness

摘要:本研究探究了钒（V）含量对磨片用7Cr17不锈钢显微组织、析出碳化物、力学性能的影响。通过金相显微镜、扫描电子显微镜、洛氏硬度计等对试样进行检测和分析，确定了适宜的V添加量。结果表明，不锈钢组织由板条马氏体、碳化物和残余奥氏体构成。随着V的添加，组织中碳化钒（VC）含量增加，弥散程度增大，但当V含量增至0.5%后，碳化物出现聚集长大现象。细小弥散的VC碳化物可有效阻碍位错运动，提升不锈钢的洛氏硬度；添加少量V时，细小弥散的VC可以钉扎位错，延缓裂纹萌生，提高试样的冲击韧性；然而，过量添加V会导致碳化物在晶界或晶内大量析出，造成应力集中，使材料脆化。加入0.15%~0.3%的V时，VC弥散程度高，不锈钢综合性能最好。

Abstract:This study investigated the effects of vanadium(V) content on the microstructure， precipitated carbides， and mechanical properties of 7Cr17 stainless steel used for grinding discs. The specimens were examined and analyzed using a metallurgical microscope， scanning electron microscope， Rockwell hardness tester， and other equipment， thereby determining an appropriate amount of V addition. The results revealed that the stainless steel microstructure consisted of lath martensite， carbides， and retained austenite. With the addition of V， the amount of vanadium carbide (VC) in the microstructure increased and its dispersion degree enhanced； however， when the addition amount reached 0.5%， carbide aggregation and growth occurred. The finely dispersed VC carbides effectively hindered dislocation movement， improving the Rockwell hardness of the stainless steel. When a small amount of V was added， the finely dispersed VC could pin dislocations， delay crack initiation， and enhance the impact toughness of the specimens. However， excessive V addition led to the massive precipitation of carbides at grain boundaries or within grains， resulting in stress concentration and material embrittlement. When 0.15% to 0.3% of V was added， the VC exhibited a high degree of dispersion， and the stainless steel demonstrated the best overall performance.