What are caused on boiler tubes because of faulty manufacturing?

Die marks are indicative of issues that can arise from the manufacturing process of boiler tubes. These marks are often a result of inadequate machining or handling, leading to uneven surfaces or imperfections. This can compromise the integrity of the boiler tubes, affecting their performance and durability. The presence of die marks suggests that the manufacturing process did not meet the required standards, potentially leading to problems during operation, such as stress concentrations that could lead to failures.

While scratches, dents, and corrosion can occur in boiler tubes, they are typically associated with usage, handling, or environmental factors rather than faults in the manufacturing process. Scratches may result from contact with other objects, dents can occur due to improper handling or impact, and corrosion is generally induced by environmental factors or chemical reactions over time. In contrast, die marks specifically point to deficiencies that originated during production.