超高强高韧Cr-Ni-Mo和Mn-Mo-Ti马氏体钢的耐磨性

Wear resistance of ultra-high strength and high toughness Cr-Ni-Mo and Mn-Mo-Ti martensitic steel

利用扫描电镜和电子背散射衍射技术对Cr-Ni-Mo和Mn-Mo-Ti超高强高韧性马氏体钢的耐磨性进行分析。冲击磨损结果表明：在2.5 J冲击能量作用下,随冲击磨损时间的增加,Cr-Ni-Mo钢的耐磨性呈先上升后下降的趋势,耐磨性可高达5.8 h·g-1。而Mn-Mo-Ti钢的耐磨性则随着冲击时间的增加呈逐步下降的趋势,由5.9 h·g-1逐步降至3.2 h·g-1。Cr-Ni-Mo钢和Mn-Mo-Ti钢的磨损机制均由犁削机制、塑变疲劳机制和磨料嵌入机制组成,其中犁削机制为主要的磨损机制。在近磨面区（距磨面20~300μm）,马氏体基体快速分解为铁素体和渗碳体的混合组织。Cr-Ni-Mo钢中析出的细小弥散的析出相有助于改善其耐磨性,而Mn-Mo-Ti钢中析出的粗大碳化物导致Mn-Mo-Ti钢的耐磨性不断降低。

The wear resistance of the Cr-Ni-Mo and Mn-Mo-Ti ultrahigh strength and high toughness martensitic steel was analyzed by using scanning electron microscopy（SEM）and electron back scattering diffraction technology（EBSD）.The impact wear results show that the wear resistance of Cr-Ni-Mo steel exhibits the tendency of first increases and then decreases with increase of impact time under the impact energy of 2.5 J,and up to 5.8 h·g-1.However,the wear resistance of Mn-Mo-Ti steel decreases gradually with increase of impact time,and the value of wear resistance decreases from 5.9 h·g-1to 3.2 h·g-1.The wear mechanism of the Cr-Ni-Mo and Mn-Mo-Ti steel consist of plough cutting,plastic fatigue and abrasive embedding mechanism,and the plough cutting mechanism dominates wear process.Martensite decomposes rapidly into a mixture of ferrite and cementite near the grinding zone on ground surface（20-300μm to ground surface）.And the fine dispersed precipitated phase can improve the wear resistance of Cr-Ni-Mo steel.However,the wear resistance of Mn-Mo-Ti steel is continuously reduced due to the large carbide precipitated phase.