耐磨涂层对40CrNiMoA合金钢拉伸性能的影响

Effects of Wear-resistant Coating on Tensile Property of 40CrNiMoA Alloy Steel

选用WC-12Co粉末,采用超音速火焰喷涂技术,在40CrNiMoA合金钢表面制备耐磨涂层,研究了合金钢拉伸件基体直径(5、10、15 mm)、涂层厚度(0.1、0.3、0.5 mm)对试样拉伸性能的影响。利用扫描电镜对拉伸断口形貌进行观察。结果表明:在拉伸过程中,试样均在屈服阶段后发生宏观的涂层剥落失效现象;相对于原试样,涂层的伸长率都有明显下降,下降幅度最大达12.3%;当涂层厚度为0.3 mm时,基体直径为5 mm的试样抗拉强度有明显下降;基体直径为10 mm,涂层的厚度变化时,试样的抗拉强度与屈服强度变化不大。试样的微观断口局部区域存在解理台阶,呈现局部脆断特征。

Taking WC-12Co powder,the wear-resistant coating was prepared on the surface of 40 CrNiMoA alloy steel by high velocity oxyfuel spraying method.The effects of substrate diameter(5 mm,10 mm,15 mm)and coating thickness(0.1 mm,0.3 mm,0.5 mm)on the tensile property of the specimens were studied,and the tensile fracture morphology was analyzed by scanning electron microscope.The results show that during the tensile process,the macroscopic spalling failure of coating of the specimen occurs after the yield stage.Compared with the original specimen,the elongation of all specimens obviously reduces,the maximum decline is 12.3%.When the coating thickness is 0.3 mm,the tensile strength of the specimens with the diameter of 5 mm decreases obviously.When the substrate diameter is 10 mm and the thickness of the coating changes,the variations of the tensile strength and yield strength of the specimens are small.There are cleavage steps in the miro fracture local region,which shows local brittle characteristics.