Success Stories : Case Studies
Variation in the Heat Treatment Process
SITUATION:
A manufacturing company discovered excessive variation in their heat treatment process. Although they had received very few customer complaints, the company was aware that the impact could lead to incorrect hardness and microstructure of the material. In turn, this could generate product failures and warranty resulting in product recall.
CHALLENGE:
Internally, the quality department monitored hardness, and during a 12-month period, there were 40 instances of rework and scrap that were attributed to incorrect hardness.
REASONS:
Several weeks of investigation and statistical analysis uncovered the following issues:
- The hardness tester did not have an acceptable level of accuracy.
- The temperature of the chemical tanks used in the heat treatment process were not properly controlled.
- Parts were quenched with insufficient water.
- Chemical concentration of the tanks was not properly controlled.
SIMONS-WHITE PROVIDED:
The solutions involved:
- Establishing an alarm system to monitor the temperature and chemical concentration of the tanks.
- Focusing more on controlling process parameters. Measuring the hardness of components was used for verification purposes.
- Developing a training program for the operators in the area to demonstrate to them the impact of the heat treatment process on steel structure.
RESULTS:
The savings that resulted from this project were over $750,000. However, since the project was not done because of an external customer complaint, the financial savings were attributable to cost avoidance.
