45 Spatter

Spatter is a discontinuity consisting of metal particles expelled during fusion welding that do not form part of the weld. Only spatter which adheres to the base metal is a concern.

Typically, spatter is not considered to be a serious discontinuity unless it interferes with subsequent operations, such as nondestructive examination. However, large globules of spatter may have sufficient heat to cause a localized heat affected zone on the base metal surface and having a similar effect as an arc strike. Also, the presence of spatter on the base metal surface could provide a local stress riser, which could cause problems during service of the finished product.

Spatter detection is achieved by visual examination (VT).

Spatter Prevention

Spatter can be reduced or possibly prevented by reducing the welding current and arc length. Anti-spatter spray is also available to prevent spatter for many welding applications.

For GMAW and FCAW, the addition of argon to the shielding gas mixture can drastically reduce spatter. Using spray transfer with GMAW instead of short circuiting is likewise very effective in reducing spatter.