Mechanical Properties and Microstructures of Narrow Gap Orbital Welded P91 Steel

Abstract

This article deals with the results of mechanical testing and structural analysis of sections of narrow gap orbital welded P91 steel on tube OD 355.6 x 40 mm. The evaluation of mechanical properties was based on tensile test at room temperature on mini-tensile specimens and on measurement of modulus of elasticity. Weld was cut longitudinally into 9 narrow slices by using waterjet. From these slices 108 flat mini-tensile specimens (dimensions of gauge is 2 x 2 mm) were prepared. In experimental part microstructure evaluation and documentation of fracture surface of each mini-tensile specimen were carried out. The aim of these experiments was to assess the mechanical properties of the individual sections of the weld (base metal, heat affected zone and weld metal). These data can be used for new approaches of FEM modelling of welds considering heat affected zone like a combination of different materials with different mechanical properties, which connect the thermally unaffected base metal and weld metal.

The Effect of Long‐Term Ageing on Microstructural Properties and Laves Phase Precipitation of Welded P91 and P92 Steels

“…A critical part of weld joints is the heat affected zone (HAZ) which consists of several different regions with different mechanical and microstructural properties: coarse grain HAZ (CG HAZ), fine grain HAZ (FG HAZ), and intercritical HAZ (IC HAZ). [ 14 ] The knowledge of microstructural degradation in individual HAZ regions is necessary for the estimation of residual life of the weld joints.…”