Inverse Thermal Analysis of Stainless Steel Deep-Penetration Welds Using Volumetric Constraints

Case-study inverse thermal analyses of 304L, 21Cr-6Ni-9Mn, and Grade EH-36 stainless steel deep-penetration welds are presented. These analyses employ a methodology that is in terms of numerical-analytical basis functions for inverse thermal analysis of steady-state energy deposition in plate structures. The results of the case studies presented provide parametric representations of weld temperature histories that can be adopted as input data to various types of computational procedures, such as those for prediction of solid-state phase transformations. In addition, these temperature histories can be used to construct parametric-function representations for inverse thermal analysis of welds corresponding to other process parameters or welding processes whose process conditions are within similar regimes. The present study extends an inverse thermal analysis procedure applied in previous studies. This extension provides for the inclusion of volumetric constraint conditions whose two-dimensional projections are mappings onto transverse cross sections of experimentally measured solidification boundaries. This study also discusses specific aspects of the inverse-analysis methodology relevant to further development of algorithms for its application in practice.