What temperature must the weld reach for finish grinding when the temperature is below 600 degrees?

Achieving the correct temperature for finish grinding in thermite welding is crucial for ensuring the quality and integrity of the weld. A weld temperature that falls below 600 degrees Fahrenheit indicates that additional processing, such as grinding, can be carried out to refine the weld surface.

The temperature of 400 degrees Fahrenheit is significant because it is generally considered the minimum heat at which the weld could still carry out proper precision grinding without compromising the material. At temperatures below this threshold, the metal might still be too hard or brittle, which could lead to poor grinding results or potentially damage the weldment.

Choosing 400 degrees as the appropriate finish grinding temperature ensures that the weld has sufficiently cooled while still retaining enough ductility and malleability for effective machining. This temperature strikes a balance, allowing for optimal material properties during the grinding process. The other temperature options—300, 350, and 450 degrees—do not provide the same assurance of suitable material behavior for finish grinding. Thus, 400 degrees is the correct choice for performing finish grinding effectively under the given conditions.