秸秆揉切机用刀片断裂失效分析

Study on Fracture Failure of Cutters Used in a 9RZ60 Model Rubbing and Cutting Machine

对 9RZ 6 0型秸秆揉切机用刀片的断裂失效进行了宏观、微观和组织分析 ,并测定了 6 5 Mn钢刀片的化学成分。指出刀片金相组织不合理是造成断裂的主要原因 ,同时 ,由于结构设计的不合理造成的应力集中也是刀片断裂的重要原因。在实际工况试验条件下 ,确定了采用 6 5 Mn钢经淬火、等温淬火和低温充分回火的热处理工艺。

The main cause of fracture failure of a cutter used in a rubbing and cutting machine has been found in this work by macro- and micro-analyses, the analysis of chemical constitutions of the cutter made of 65Mn, and metallographic examinations. The results showed that the fracture failure was mainly resulted from unreasonable heat treatment, and the stress concentration due to improper design of the cutters frame might also lead to the failure. An experiment was done to improve the performance of the cutters, which indicated that the cutters made of 65Mn were reasonable under the proper heat treatment.