Prediction of residual stresses in high strength carbon steel pipe weld considering solid-state phase transformation effects

2011 ◽  
Vol 89 (1-2) ◽  
pp. 256-265 ◽  
Author(s):  
Chin-Hyung Lee ◽  
Kyong-Ho Chang
Keyword(s):  
Phase Transformation ◽  
Solid State ◽  
Carbon Steel ◽  
Residual Stresses ◽  
High Strength ◽  
Steel Pipe ◽  
Solid State Phase Transformation

Simple Benchmark Problems for Finite Element Weld Residual Stress Simulation

2013 ◽  
Author(s):  
Mike C. Smith ◽  
Steve Bate ◽  
P. John Bouchard
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Phase Transformation ◽  
Solid State ◽  
Residual Stresses ◽  
Benchmark Problems ◽  
Transient Temperature ◽  
Beam Specimen ◽  
Weld Residual Stress ◽  
Solid State Phase Transformation

Finite element methods are used increasingly to predict weld residual stresses. This is a relatively complex use of the finite element method, and it is important that its practitioners are able to demonstrate their ability to produce accurate predictions. Extensively characterised benchmark problems are a vital tool in achieving this. However, existing benchmarks are relatively complex and not suitable for analysis by novice weld modellers. This paper describes two benchmarks based upon a simple beam specimen with a single autogenous weld bead laid along its top edge. This geometry may be analysed using either 3D or 2D FE models and employing either block-dumped or moving heat source techniques. The first, simpler, benchmark is manufactured from AISI 316 steel, which does not undergo solid state phase transformation, while the second, more complex, benchmark is manufactured from SA508 Cl 3 steel, which undergoes solid state phase transformation during welding. A number of such beams were manufactured using an automated TIG process, and instrumented with thermocouples and strain gauges to record the transient temperature and strain response during welding. The resulting residual stresses were measured using diverse techniques, and showed markedly different distributions in the austenitic and ferritic beams. The paper presents the information necessary to perform and validate finite element weld residual stress simulations in both the simple austenitic beam and the more complex ferritic beam, and provides performance measures for the austenitic beam problem.

scholarly journals Analysis of a High-Strength Steel SMAW Database

2021 ◽  
Vol 100 (12) ◽  
pp. 410-420
Author(s):  
KRISHNA SAMPATH ◽  
Keyword(s):  
Phase Transformation ◽  
Solid State ◽  
Carbon Content ◽  
High Strength Steel ◽  
High Strength ◽  
Regression Equations ◽  
Austenite Decomposition ◽  
Impact Properties ◽  
Transformation Temperatures ◽  
Solid State Phase Transformation

Recently, Dr. Glyn M. Evans posted a large shielded metal arc (SMA) weld metal (WM) database on the ResearchGate website (researchgate.net). This database contains more than 950 WM compositions, along with their respective WM tensile and Charpy V-notch (CVN) impact properties. In particular, the CVN impact properties list the test temperatures that achieved 28 and 100 J impact energy for each WM composition. While the availability of this SMA WM database is a valuable and rare gift to the welding community, how could the welding community analyze this database to gain valuable insights? This paper utilizes a constraints-based model (CBM) as a simple and effective framework to organize and analyze this very large Fe-C-Mn SMA WM database. A CBM is built on the metallurgical principle that one needs to lower relevant solid-state phase transformation (i.e., austenite decomposition) temperatures to improve WM strength and fracture toughness while simultaneously reducing carbon content and Yurioka’s carbon equivalent number (CEN) to improve the weldability of high-strength steels. To this end, a CBM identifies and simultaneously solves several statistical (regression) equations that relate the chemical composition of high-strength steel WM with Yurioka’s CEN and selected solid-state phase transformation temperatures related to austenite decomposition. The results of the current effort demonstrate that the analysis of Evans’s shielded metal arc welding database using a CBM as a framework reaffirms that controlling carbon content, the value of the CEN, and calculated solid-state phase transformation temperatures, particularly the difference between the calculated Bs (bainite-start) and Ms (martensite-start) temperatures, is critical to developing and identifying high-performance, high-strength steel welding electrodes. A dual approach that manipulates the contents of principal alloy elements such as C, Mn, Ni, Cr, Mo, and Cu, and adds controlled amounts of Ti, B, Al, O, and N, appears to offer the best means to lower relevant solid-state phase transformation temperatures to produce high-strength and high-toughness WMs.

Solid-state phase transformation and strain hardening on the residual stresses in S355 steel weldments

2019 ◽  
Vol 265 ◽  
pp. 173-184 ◽  
Author(s):  
Jiamin Sun ◽  
Jonas Hensel ◽  
Jakob Klassen ◽  
Thomas Nitschke-Pagel ◽  
Klaus Dilger
Keyword(s):  
Phase Transformation ◽  
Solid State ◽  
Residual Stresses ◽  
Strain Hardening ◽  
Solid State Phase Transformation

Numerical simulation of P91 pipe welding including the effects of solid-state phase transformation on residual stresses

2007 ◽  
Vol 221 (4) ◽  
pp. 213-224 ◽  
Author(s):  
A H Yaghi ◽  
T H Hyde ◽  
A A Becker ◽  
W Sun
Keyword(s):  
Phase Transformation ◽  
Solid State ◽  
Residual Stresses ◽  
Wall Thickness ◽  
Outer Diameter ◽  
Fe Method ◽  
P91 Steel ◽  
Weld Region ◽  
Solid State Phase Transformation ◽  
Hoop Stresses

The methodology of numerically simulating residual stresses in a welded P91 pipe section is described. The finite element (FE) method has been applied to simulate residual axial and hoop stresses generated in the weld region and heat affected zone (HAZ) of an axisymmetric 50-bead circumferentially butt-welded P91 steel pipe, with outer diameter of 145 mm and wall thickness of 50mm. The FE simulation consists of a thermal analysis which is followed by a sequentially-coupled structural analysis. Solid-state phase transformation (SSPT), which is characteristic of P91 steel during welding thermal cycles, has been modelled in the FE analysis by allowing for volumetric changes in steel and associated changes in yield stress due to austenitic and martensitic transformations. Phase transformation plasticity has also been taken into account. Preheat and interpass temperature control has been included in the modelling process. Thermally-obtained temperature contours indicate the size of the weld region, parent metal penetration, and HAZ. Residual axial and hoop stresses have been depicted through the pipe wall thickness as well as along the outer surface of the pipe. The results indicate the importance of including SSPT in the simulation of stresses during the welding of P91 steel.

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