What can excessive heat during welding cause to the welded material?

Excessive heat during welding can lead to lower tensile strength in the welded material. This phenomenon occurs because excessive temperatures can affect the microstructure of the metal. When the heat exceeds recommended levels, it can cause grain growth in the material, leading to a coarsened grain structure that diminishes the material's strength. High heat can also result in the formation of heat-affected zones (HAZ) that may exhibit reduced strength and altered properties compared to the base material.

Deterioration of mechanical properties, such as tensile strength, can make the weld joint and surrounding area more susceptible to failure under load. Therefore, controlling the welding heat input is crucial to maintaining the integrity and performance of the welded joint.

In contrast, while improved ductility, increased corrosion resistance, and enhanced weld appearance might seem beneficial, these are not direct results of excessive heat during the welding process. Instead, excessive heat can compromise these properties, making the consideration of temperature control in welding processes essential for achieving durable and reliable welds.