Crankshaft Hardness Quality Evaluation of Passenger Car

A crankshaft is a part of the main engine components and plays a critical role in car performance. The crankshaft component consists of journals, pins, and flange that experience induction hardening treatment to increase their hardness. Hardness case depth represents important hardness criteria achieved by the depth of induction hardening process. This paper aims to evaluate crankshaft hardness quality by analyzing hardness case depth measurement. The control chart shows the results, which presents process stability to indicate abnormal processes. The capability process is also performed to process consideration. Evaluation results show hardness case depth is not at its best performance even though process capability meets product requirements. Affected factors to process stability are manpower, method, material, measurement, machine and environment. Implemented improvements based on the problem root cause to eliminate influenced factors and achieve stable process are delivered.