TY - JOUR
T1 - Liquid metal induced embrittlement of a nitrided clutch shell of a motorbike
AU - Ding, Ning
AU - Xu, Na
AU - Guo, Weimin
AU - Shi, Junbo
AU - Zang, Qishan
AU - Wu, Chi-Man Lawrence
PY - 2016/3
Y1 - 2016/3
N2 - The failure mechanism of a clutch shell made from SPCC nitrided steel was analyzed. The component sustained multiple brittle fractures during assembly. Under SEM examination, the fracture surface was found to have facet and cleavage grain appearance. It was predicted that the cleavage fractures started from sites of intergranular fractures. XRD results showed that the nitriding layer contained Fe3N (60 wt.%) and Fe4N (40 wt.%). It is noted that Fe3N is more brittle than Fe4N. An impact test was carried out to compare the impact resistance of the failed and normal components. EDS analysis was also carried out, and it was found that the fracture surface contained zinc, which was not an element specified for the SPCC steel or the nitriding salt. As the salt bath nitriding process operated at a temperature higher than the melting point of zinc, failure was most likely due to liquid metal zinc induced embrittlement, as a result of localized salt bath material contamination with zinc.
AB - The failure mechanism of a clutch shell made from SPCC nitrided steel was analyzed. The component sustained multiple brittle fractures during assembly. Under SEM examination, the fracture surface was found to have facet and cleavage grain appearance. It was predicted that the cleavage fractures started from sites of intergranular fractures. XRD results showed that the nitriding layer contained Fe3N (60 wt.%) and Fe4N (40 wt.%). It is noted that Fe3N is more brittle than Fe4N. An impact test was carried out to compare the impact resistance of the failed and normal components. EDS analysis was also carried out, and it was found that the fracture surface contained zinc, which was not an element specified for the SPCC steel or the nitriding salt. As the salt bath nitriding process operated at a temperature higher than the melting point of zinc, failure was most likely due to liquid metal zinc induced embrittlement, as a result of localized salt bath material contamination with zinc.
KW - Liquid metal induced embrittlement
KW - Failure
KW - Fracture
KW - SPCC steel
UR - http://www.scopus.com/inward/record.url?scp=84962163337&partnerID=8YFLogxK
UR - https://www.scopus.com/record/pubmetrics.uri?eid=2-s2.0-84962163337&origin=recordpage
U2 - 10.1016/j.engfailanal.2015.08.008
DO - 10.1016/j.engfailanal.2015.08.008
M3 - RGC 21 - Publication in refereed journal
SN - 1350-6307
VL - 61
SP - 54
EP - 61
JO - Engineering Failure Analysis
JF - Engineering Failure Analysis
ER -