316 Stainless Filler Question

Date 02-21-2012 13:44

Hi

As a general rule the yield point for welds are substantially higher than for the base materials. (There would be exceptions for cold rolled sections / plate, but this is seldom the case for major structures.) This means that the material will almost always yield in the base metal and not the weld metal. Designs are therefore based on the yield strength of the base metal. If there is any situation where there may be any doubt regarding this, then the designer will call for all weld tensile tests to be performed on the WPS qualification test pieces, to proove that the weld metal yield strength is at least as high as for the base metal. (In some applications, it is a requirement for the weld metal to be substantially stronger than the base metal, in which case a minimum yield strength will be specified that is higher than the base metal yield stength.)

In other words, just assume the filler has the same yield as the base metal, unless there is a good reason to doubt this. If you are interested in "typical" filler yield stengths, these are often given on filler data sheets.

Regards
Niekie

By Solluz

Date 02-23-2012 23:13

Hi, For design, obviously make sure you are following the applicable code. For example, AWS D1.6 (Structural SS), Table 2.1 provides design criteria for stresses in welds (CJP, PJP, fillet welds and Plug and Slot welds). For example, some of the criteria is based on the lesser of: values for base metal or filler metal (ultimate tensile strength). The A5 filler metal standards do not list yield strength values for any of the stainless fillers, and the A5.9 standard for bare wires and electrodes do not even list UTS values. Usually for say pressure piping or vessels where CJP welds are used, the strength of the weld matches or exceeds the base material so the design is based on code calculations for the base materials being welded. The codes provide allowable stresses that must be considered.

Regards,

Sol