Interpass temperature is the temperature of the base metal in and adjacent to the weld joint prior to depositing and additional pass (weld). Maintaining and measuring interpass temperature should be done carefully. Different materials require different levels of preheat and interpass temperature. For this reason it is extremely important that both prehat and interpass temperature be specified […]
Preheating of structural steels is carried out primarily to slow the cooling rate after welding and prevent the formation of martensite. Martensite makes the weld and the heat affected zone (HAZ) very hard and brittle. This newly formed microstructure is susceptible to cracking. By slowing the cooling rate we reduce or eliminate the formation of […]
T-1, or ASTM A514 is a high strength steel which is quenched and tempered to provide yield strengths of over 100,000psi (over 690MPa). The name “T-1” is a trademark of Arcelor Mittal and not an ASTM, AISI or part of other organization’s standard numbering system. ASTM A514 is primarily used as a structural steel and […]
Preheating steel before welding is common practice. Sometimes we apply heat after we are done welding as well. Other times we apply heat between passes to maintain the minimum interpass temperature. Many use preheat simply because it is written in the WPS, but not really understand why it is necessary. Preheating is used for […]
