不同基体硬质合金刀具铣削不锈钢的试验研究

Experimental Study on Milling Stainless Steel by Cemented Carbide Tools with Different Matrix

采用不同基体材质的硬质合金刀具进行1Cr18Ni9Ti不锈钢干式铣削试验,对不同铣削时间的腐蚀前和腐蚀后刀具进行扫描电子显微镜(SEM)和元素能谱(EDS)检测,对比分析刀具的寿命和失效机理,以获得在1Cr18Ni9Ti不锈钢干式铣削条件下刀具基体材料的选择依据。研究结果表明:刀具的主要失效机理包括粘结磨损、氧化磨损、热疲劳和边界磨损;不锈钢铣削所具有的断续切削和粘屑的切削工况是造成刀具热疲劳的根本原因;三种基体硬质合金刀具表现出相同的热疲劳特征;刀具的边界磨损情况与基体的韧性呈现很好的对应关系,韧性越差,边界磨损越严重;在选择干式铣削不锈钢刀具的时候,不能以单一韧性或硬度指标作为选择刀具基体的依据,而是选择综合力学性能合适的基体材质。

Dry milling tests were conducted for 1 Cr18 Ni9 Ti stainless steel by using cemented carbide tools with different matrix materials.The tools with different milling time were observed before and after corrosion by SEM and EDS,and the tool life and failure mechanism were compared and analyzed to obtain the basis for tool matrix material selection in dry milling of 1 Cr18 Ni9 Ti stainless steel.The experimental results show that adhesive wear,oxidation wear,thermal fatigue and boundary wear are the main failure mechanisms of the tools.The cutting condition of intermittent cutting and grinding chips in stainless steel milling is the basic reason for thermal fatigue of the tool.The cemented carbide tools with the three kinds of matrix show the same characteristics of thermal fatigue.There is a good corresponding relationship between the boundary wear of the tool and the toughness of the matrix.The worse the toughness,the more serious the boundary wear.When choosing the tools for dry milling of stainless steel,the single index of toughness or hardness can not be used as the basis for selecting tool matrix,while the matrix material with appropriate comprehensive mechanical properties can be selected.