51吃瓜

???? ????? ?? ?????? ????? ??? ???? ?? ??? ??? ?? ???? ?? ????? ?? ???? ???. ???? ?? ??? ????? ?? ?? ???? ?? ????? ???? ?? ????? ??? ???? ???? ?? ??? ???? ?? ???? ?? ????? ????? ??? ????? ?? ?? ???? ???: (1) ?????? ????? ?????: (2) ???? ???? ???? ???: ???? ?????? ????? ??? ???? ?? ???? ????? ????? ???? ?? ??? ????? ???? ?? ????? ?? ?????? ??? ?????? ?? ???????? ?? ?? 2. ??? ???? ?? ???? ????? ?????? ????? ???? ?????? ????: ??? ?? ????? ?????? ?? ??? ???? ?? ???? ?? improving ???? ????? ?? ???? ?? ?????? ??? ?? ????? ?? ??? ?? ??? ???? ?? ???? ?? ????? ??? Manufacturing process issues: 2. Uneven temperature: manufacturing process, if the temperature is not properly controlled, it may result in uneven temperature distribution, which may cause uneven stress distribution in the material and lead to cracks at stress concentration points ??? ????? ???? ???? ???? ?????: ???? ?????? ??? ?????? ??? ????? ?? ???? ???? ???? ????? ?? ??? ??? ???? ???. ?? ?? ????? ???? ?? ???? ?? ?? ?? ????? ??? ???? ???? ?? ???? ?? ???? ?? ?? ??? ????? ?? ??? ???? ??? ????? ??? ????: ??? ????? ??? ?????? ????? ?? ????? ?? ?????? ????? ?? ???? ???? 2 ??? ????? ??????? ?????: ??? ??????? ????? ????? ?????? ?? ?? ????? ??????? ????? ???? ?? ?? ????? ????? ?? ??? ????? ?? ???? ?? ????? ???? ????? ?? ??? ???? ?????? ??: ??? ?????? ??? ??? ????? ???? ????? ??? ?? ????? ????? ?? ???? ?? ????? ?? ???? ?? ?? ??? ????? ???? ?? ??? ??? ?? ???? ??? ?? Heat treatment problems: 2. Improper heat treatment: improper control of parameters such as quencing temperature and time may lead to uneven material structure, excessive internal stress, and other problems, thereby cracking causes ????? ?? ???? ??? ?? ????? ???? ?? ??? ????? ???: ????? ??? 45 ????? ?? ????? ???? ?????? ?? ????? ?? ???? ??? ?? ????? ?? ????? ????? ???? ????? ???? ??? ?? ?? stress ?? ????? ???? ???? ?? ????? ?? ??? ?????? ?? ?? ???? ????? ??? ????? ??? ????? ?? ???? ???? ?? ????? ??? ??? ???? ?? ??? Usage and maintenance factors: 1. excessive load: excessive load on bearings may cause bearing parts to break. 2 ???? ?????? ??? ???????? ???? ??? ??? ????? ??? ????? ?? ????? ??????? ??? ??????? ?? ??????? ?? ?? ????? ?? ???? ?????? ??? ???????? ???? ????? ?? ???? ?? ??? ?? ???? ??.