Which of the following statements is true regarding brazing?

Brazing is a metal-joining process that typically operates at higher temperatures than soldering, and it uses a filler metal that has a melting point above 450 °C (842 °F). One of the key characteristics of brazing is that it tends to produce less distortion in the joined materials compared to fusion welding. This is primarily because brazing joints rely on the filler metal to bond without melting the base materials, thereby minimizing thermal stress and distortion that often occurs when base materials are heated extensively in welding.

Additionally, brazing can be more controlled in terms of the heat applied, as it usually does not melt the base materials, contrasting with welding processes that do melt and fuse the base metals together. This property is significant in applications where maintaining the integrity and shape of the components is critical, such as in delicate assemblies or precision engineering.

The other statements do not accurately reflect the characteristics of brazing. For instance, it actually requires more heat than soldering, does involve a flux to prevent oxidation during the heating process, and does not fundamentally rely on chemical reactions to generate heat. Understanding these distinctions can help solidify your knowledge of brazing as a distinct and beneficial joining process in metallurgy and pipeline work.