W6Mo5Cr4V2钢模具淬火开裂失效分析

Failure analysis on quenching cracking of W6Mo5Cr4V2 steel die

采用火花放电直读光谱仪、数显维氏硬度计、光学显微镜以及扫描电镜,对W6Mo5Cr4V2钢模具开裂失效件的化学成分、表面硬度、断口形貌及显微组织进行检测和分析。结果表明:由于模具原材料轧制或锻造工艺不合理,铸造枝晶组织未能改善,且轧制及锻造过程中,基体中网状共晶碳化物未打碎,沿网状共晶碳化物脆性急剧增大,致使热处理过程中出现淬火开裂。

Using spark discharge direct reading spectrometer,digital Vickers hardness tester,optical microscope and scanning electron microscope,the chemical composition,surface hardness,fracture morphology and microstructure of W6 Mo5 Cr4 V2 steel mold cracking failure parts were detected and analyzed.The results show that due to the unreasonable rolling or forging process of die raw materials,the casting dendrite structure can not be improved,and during the rolling and forging process,the reticulated eutectic carbides in the matrix are not broken,and the brittleness along the reticulated eutectic carbides increases sharply,resulting in quenching cracking in the heat treatment process.