What type of penetrant indication suggests a cold shut on a casting's surface?

What type of penetrant indication suggests a cold shut on a casting's surface?

• A. Dotted or smooth continuous line
• B. A series of fine cracks
• C. A pronounced curve
• D. A sharp point

Answer: (A)

The indication of a cold shut on a casting's surface is best represented by a dotted or smooth continuous line. A cold shut occurs when two streams of molten metal fail to fuse completely during the casting process, leaving a visible discontinuity on the surface. This discontinuity often presents as a line or seam that follows the contour of the casting, and it's typically smooth or dotted rather than jagged. The other types of indications, such as a series of fine cracks, may suggest different issues like thermal stress or inadequate material flow, while a pronounced curve or a sharp point might indicate other forms of defects unrelated to cold shuts. Understanding the characteristics of different types of surface indications is crucial for accurate defect identification in casting processes.

The indication of a cold shut on a casting's surface is best represented by a dotted or smooth continuous line. A cold shut occurs when two streams of molten metal fail to fuse completely during the casting process, leaving a visible discontinuity on the surface. This discontinuity often presents as a line or seam that follows the contour of the casting, and it's typically smooth or dotted rather than jagged.

The other types of indications, such as a series of fine cracks, may suggest different issues like thermal stress or inadequate material flow, while a pronounced curve or a sharp point might indicate other forms of defects unrelated to cold shuts. Understanding the characteristics of different types of surface indications is crucial for accurate defect identification in casting processes.