Final answer:
The type of weld that forms a triangular cross section in a tee joint is called a fillet weld. This weld is efficient in material use and effective for joining metal pieces at a right angle.
Step-by-step explanation:
The weld type that has a triangular cross section when a tee joint is welded is known as a fillet weld. Fillet welds are commonly used when joining two pieces of metal at a right angle to each other in a 'T' shape. This type of weld is preferred for its efficiency in the use of welding material and its effectiveness in joining parts together under a variety of conditions.
Fillet welds are characterized by their triangular shape which is formed by the welding process. The size of the fillet weld is typically determined by the thickness of the metal pieces being joined together, with the objective of creating a weld that is strong enough to meet the requirements of the design without using excessive welding material. Fillet welds are versatile and can be applied using different welding techniques, including Shielded Metal Arc Welding (SMAW), Gas Metal Arc Welding (GMAW), and Gas Tungsten Arc Welding (GTAW).