What is in this article?:
Defects can be defined as imperfections that exceed certain limits. Here are some facts about common and not so common forging defects that come from actual forging operations or from post forging operations typical of many forge plants.
When we think of all the ways of making a part from metal, forging stands out as the best way to achieve top quality and performance of vital parts. Forgings sometimes cost more than parts produced by other means, e.g. casting, powder metal, weldments, etc. But forging quality is worth it to the designer if he continues to experience high reliability from forged products. As a commercial says, he “expects more and he gets more.”
Or does he? Sometimes forgings are made improperly and fail in service. The customer becomes unhappy with not only the forging supplier, but also with his choice of forging as the production process. When a product fails, there not only is the loss of customer confidence in selecting forging for the next critical part, but there is also the specter of product liability.
The forging company’s quality system may have failed or someone may have failed to practice good workmanship. It has been proven time and again that systems do fail no matter how elaborate the inspection procedures.
To make matters worse, if one forge shop fails to consistently meet good quality standards, it can blemish the reputation that all forgings have for reliability.
A good quality program begins with an attitude — an attitude of making it right the first time, of asking “what can I do to help?” This is pride of workmanship.
Most employees sincerely want to display workmanship and they do a better job if they know and understand why they are doing what they are doing. Quality conscious operators stop and ask when they see something unusual happening during forging, especially when then feel encouraged to ask an “informed question.” Untrained employees may not show the desired interest.
This discussion deals with the kinds of defects that form during the forging process. They sometimes are traceable to the starting material but more often to the forging process itself. The discussion that accompanies each description of a defect provides possible cures for that type of defect. In some cases, there is more than one cause. Options are discussed for each type of material or forging process.