１．結論・調査品は、パイプ部エンジン後方内周側に生じていたプリクラック

１．結論・調査品は、パイプ部エンジン後方内周側に生じていたプリクラックをきっかけに延性破壊したものと推測する。・破面にアルマイト処理由来と思われる元素(S)が検出され、また破損部付近内周面にかじりが認められることから、（表面処理より前の）鋳造工程で離型時にかじりが発生し、その負荷によってエンジン後方側の内周にプリクラックが発生したと推測する。プリクラック起点部断面には鋳造欠陥は認められなかったため、鋳造品質がプリクラック発生に影響したかは不明である。ただし、破断部周辺に破断チルの巻き込みが複数認められるため、鋳造品質の改善が必要である。

ผลลัพธ์ (อังกฤษ) 1:

1. Conclusion : It is presumed that the inspected product suffered ductile failure due to a pre-crack that had occurred on the inner periphery of the pipe at the rear of the engine. ・Element (S), which is thought to be derived from alumite treatment, was detected on the fracture surface, and galling was observed on the inner circumferential surface near the fractured part, indicating that galling occurred during mold release during the casting process (prior to surface treatment). It is assumed that the load caused a pre-crack to occur on the inner periphery of the rear side of the engine. Since no casting defects were observed in the cross section of the precrack starting point, it is unclear whether the casting quality influenced the occurrence of precracks. However, since multiple fracture chills were observed around the fracture, it is necessary to improve the casting quality.

ผลลัพธ์ (อังกฤษ) 2:

1 conclusion
It is assumed that the investigation product is ductile fracture caused by the pre crack formed in the rear side of the pipe part engine.
Since the element (s) which is considered to be the origin of the alumite treatment is detected on the fracture surface, and the clad is recognized in the inner peripheral surface of the breakage portion, it is assumed that the clad occurs at the releasing process in the casting process (before the surface treatment), and the precrack is generated in the inner periphery of the engine by the load. Since no casting defect was found in the cross section of the precrack point, it was unclear whether the casting quality affected the precracking. However, since a plurality of crushed chills are allowed to be formed around the break portion, it is necessary to improve the casting quality.

ผลลัพธ์ (อังกฤษ) 3:

1. Conclusion
Presumably, the investigated product took the opportunity of the pre-crack generated on the inner peripheral side behind the engine in the pipeline part, which destroyed the ductility.
Because the element (S) considered as the reason for alumina film treatment was detected on the cross section, and adhesion was found on the inner peripheral surface near the damaged part, it is presumed that adhesion occurred during demoulding in the casting process (before surface treatment), and pre-cracks were generated on the inner periphery of the rear side of the engine due to this load. Because no casting defects are found in the section at the beginning of pre-cracking, it is not clear whether the casting quality affects the occurrence of pre-cracking. However, because many cracks were found around the fracture, it is necessary to improve the casting quality.