If a high current density is flowing from a well-coated line through the soil and onto a bare foreign line, what could result?

When high current density flows from a well-coated pipeline into the soil and comes into contact with a bare foreign pipeline, localized corrosion can occur as a result of the electrochemical processes that are intensified in areas where the protective coating is absent.

The well-coated line is designed to minimize corrosion by preventing galvanic cells from forming on its surface. However, when current migrates to a bare section of another line, it creates a situation where the foreign line can become anodic in relation to the well-coated line. This leads to localized corrosion at the point of current density concentration, commonly known as a corrosion cell.

Localized corrosion can manifest in various forms, such as pitting or crevice corrosion, both of which can significantly weaken the structural integrity of the bare line over time. This effect highlights the importance of ensuring all pipelines, especially those in proximity to coated lines, are protected adequately and monitored for signs of corrosion to prevent failures.

In contrast, options such as damage to test leads, shorts in the cathodic protection (CP) system, and resistance bonding pertain to different electrical or testing scenarios and do not directly address the corrosion implications that arise from the current transfer in this situation. Thus, understanding the flow of current and its effects on