21310 Residual Stress Mitigation of Pipe Butt Joint by Using Water-Shower Cooling on Both Inner And Outer Surface of Pipe During Welding Process

AbstractTrailing intensive cooling with liquid nitrogen has successfully applied to friction stir welding of 2 mm thick 2060 Al-Li alloy. Welding temperature, plastic strain, residual stress and distortion of 2060 Al-Li alloy butt-joint are compared and discussed between conventional cooling and trailing intensive cooling using experimental and numerical simulation methods. The results reveal that trailing intensive cooling is beneficial to shrink high temperature area, reduce peak temperature and decrease plastic strain during friction stir welding process. In addition, the reduction degree of plastic strain outside weld is smaller than that inside weld. Welding distortion presents an anti-saddle shape. Compared with conventional cooling, the reductions of welding distortion and longitudinal residual stresses of welding joint under intense cooling reach 47.7 % and 23.8 %, respectively.

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Residual-Stress, Material Characterization in P22 HRSG-Pipeline Butt Joint

Volume 1: Codes and Standards ◽

10.1115/pvp2020-21077 ◽

2020 ◽

Author(s):

Ottaviano Grisolia ◽

Lorenzo Scano ◽

Francesco Piccini ◽

Antonietta Lo Conte ◽

Massimiliano De Agostinis ◽

...

Keyword(s):

Residual Stress ◽

Stress Level ◽

Outer Surface ◽

High Stress ◽

Base Material ◽

Longitudinal Direction ◽

Tangential Direction ◽

Butt Joint ◽

Hole Drilling ◽

Plane State

Abstract Previous study evaluated residual stress in a circumferential “V”-groove butt joint of a heat-recovery steam generator (HRSG) pipeline; the material was ASTM A-335-Grade P22. Aim had been to check on the influence over creep-relaxation previously found out for a tee made of the same material. The butt joint had been operating for the same period of 200,000 hours, same temperature of 528°C at almost a half pressure (0.46 Kg/mm2 vs. 1.06 Kg/mm2). X-ray diffraction (XRD) technique applied close to the weld highlighted anomalously high stress-level on the outer surface for all four butt-joint samples tested. Residual-stress over 400 MPa observed along the cylinder’s tangential direction was statically not acceptable. On the inner surface where deposited beads may have tempered adjacent base material, measurement via blind hole-drilling (BHD) technique showed a symmetrical plane-state residual-stress of 199 MPa. It was consistent with that observed via XRD on the outer surface in the cylinder’s longitudinal direction. Supposing a case of incomplete post heating planned for the weld may have explained the occurrence of being much higher than 40 MPa, value predicted after 200,000 hours. Similar influence over creep results found out for the tee and the butt joint had validated modeling welding simulation considered for both joints. A comprehensive new series of XRD tests aims now at measuring residual stress across the cylinder’s wall, both inner and outer sides. The shallow layer considered has thickness sufficient for building a map of measurements covering different depths and locations on the surface. The experimental plan includes also BHD tests supporting the XRD ones. Comparison with previous measurements roughly shows stress level increasing similarly across the cylinder’s wall from the inner side on: Average stress values, however, appear lower than previous measurements, showing better compatibility to the analysis results.

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Effects of Pipe Dimensions and Outer Surface-Buttering Weld Conditions on Residual Stress Distributions

Volume 6: Materials and Fabrication, Parts A and B ◽

10.1115/pvp2008-61402 ◽

2008 ◽

Cited By ~ 1

Author(s):

Nobuyoshi Yanagida

Keyword(s):

Residual Stress ◽

Residual Stresses ◽

Outer Surface ◽

Hoop Stress ◽

Axial Stress ◽

Butt Joint ◽

Stress Distributions ◽

The Finite Element Method ◽

Butt Joints ◽

Inner Surface

Effects of pipe dimensions and outer surface-buttering weld conditions on residual stress distributions were evaluated using the finite element method. Residual stresses were analyzed for 508–mm-diameter (500A) pipe 38.1 mm thick, 508–mm-diameter (500A) pipe 15.1 mm thick, and 267–mm-diameter (250A) pipe 15.1 mm thick. After the residual stresses at pipe butt joints were analyzed, residual stresses at these joints subjected to the outer surface-buttering welds were analyzed. Residual stresses were determined for various weld widths, thicknesses, and heat inputs. These analyses indicate that tensile axial stress occurred at inner surface of the pipe butt joint and that it decreased with increasing the outer surface buttering-weld width or heat input. They also indicate that compressive hoop stress occurred at inner surface of the joint and that outer surface-buttering weld increased it. The outer surface-buttering weld conditions that generate compressive residual stress at the inner surface of the pipe butt joints were determined.

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Experimental Assessment by Finite Elements Method of the Residual Stress State and of the Heat Flow from the Laser Weldings of the Alloys of CoCrMo Used in RPD (Removable Partial Dentures) Technology

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.399.185 ◽

2008 ◽

Vol 399 ◽

pp. 185-191

Author(s):

Cristina Bortun ◽

Nicolae Faur ◽

Anghel Cernescu ◽

Liliana Sandu

Keyword(s):

Residual Stress ◽

Finite Elements ◽

Welded Joints ◽

Welding Process ◽

Butt Joint ◽

Finite Elements Method ◽

Residual Stress State ◽

Solid Works ◽

Optimal Procedures ◽

Welding Procedure

The welded joints are used in the technology of the removable partial dentures for the rehabilitation of their metal component. The welding procedure and the adequate equipment are established according to the components dimension, the quality of the alloys used and the dentures section. The modifications within the welded structures can be investigated by means of non-destructive tests such as the radiography or the analysis with finite elements. The work was based on the experimental checking of the optimal procedures of welded joint of the alloys of CoCrMo in order to increase their durability. The welded joints were performed in a butt joint configuration with addition of material on the alloys of CoCrMo used in the technology of the framed dentures. The finite elements method was used (software Solid works 2007) in order to simulate the welding process (thermal analysis) and to assess the residual stress areas appeared after the various welding procedures.

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Design of the Equal-Loading Butt Joint for CF62 Steel

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.750.330 ◽

2015 ◽

Vol 750 ◽

pp. 330-338

Author(s):

Yu Wen Qian ◽

Jian Ping Zhao

Keyword(s):

Residual Stress ◽

Stress Concentration ◽

Large Scale ◽

Maximum Stress ◽

Welding Process ◽

High Strength ◽

Butt Joint ◽

3D Fem ◽

Stress Calculation ◽

Von Mises

High-strength steel is often used in the design and manufacture of the pressure vessel and the failure accident often happens in the weld area after used. CF62 is chosen in this paper which is the large-scale sphere steel for manufacture and the equal-loading butt joint of whose three different sizes are designed. The weld simulations of the equal-loading joints are made by 3D FEM, then the residual stress distributions and the influence of the thickness are analyzed in this paper. The results show that the equal-loading butt joint's weld toe is without stress concentration and the equal-loading butt joint can reduce the residual stress during the welding process. The thinner equal-loading butt joint has the lower residual stress. The joint designed by the equivalent Von Mises calculation has the lower stress than the one designed by the maximum stress calculation as well and the same as the weld toe's stress concentration. But the half reinforcement width of the maximum stress calculation butt joint is smaller than that of the equivalent Von Mises joint and whose welding electrode is economical, so the maximum stress equal-loading joint fits the engineering practical more.

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HRSG-Header Welds Residual-Stress Evaluation and Creep-Assessment Through the Application of Italian Code, American Standard

Volume 1B: Codes and Standards ◽

10.1115/pvp2018-84662 ◽

2018 ◽

Author(s):

Ottaviano Grisolia ◽

Lorenzo Scano

Keyword(s):

Residual Stress ◽

Residual Stresses ◽

Welding Process ◽

Butt Joint ◽

Finned Tube ◽

Cylinder Wall ◽

Key Factors ◽

Stress Evaluation ◽

Gas Tungsten Arc ◽

American Standard

Joint design, preheating, post-weld-heat treatment and operator ability are key factors for the occurrence of critical residual stresses in the welds. In particular, they may affect creep life results of the analysis: to evaluate this, their characterization requires modeling welding process, such as that carried out in the present work for ASTM A 335-Grade P22 weld. It is a weld of the two analyzed in previous work on the high-temperature-section (superheater/reheater) lower headers of the bottom-supported heat-recovery steam generator (HRSG). Present study includes modeling the only weld-lay, gas tungsten arc, manual, for the finned-tube angle joint to the cylinder. It is the same as the first of the three weld-lays for the other previously analyzed, end-plug circumferential “V”-groove butt joint. The material considered for base metal is 2¼Cr 1Mo forged, normalized, tempered with creep strain rates higher than the weld’s as it appeared from analysis of previous work. Presently, the study first compares max tangential stress evaluated by thermal analysis on the circumferential weld with the average applied normally on the joint, sustained case. Roughly, the latter one has nearly same importance as axial membrane stress on the cylinder wall for the end-plug butt joint, pressure case; it is smaller for the finned-tube angle joint. Then, study compares previous creep results obtained considering SRF = 0.9 for the finned-tube joint weld with those counting the residual-stress increase in stress analysis (different creep law’s coefficients). Finally, study compares creep results for the finned-tube joint weld obtained with and without residual-stresses (same creep power-law). The objective is to comprehend residual-stress influence over creep-redistribution and creep relaxation.

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Temperature Field and Residual Stress of Butt Welding for IN182 Plate

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i4.10.20713 ◽

2018 ◽

Vol 7 (4.10) ◽

pp. 95

Author(s):

Harinadh Vemanaboina ◽

G. Janardhana Raju ◽

Bura Sreenivas

Keyword(s):

Mechanical Properties ◽

Residual Stress ◽

Structural Changes ◽

Welding Process ◽

Industrial Applications ◽

Butt Joint ◽

Nonlinear Phenomenon ◽

Element Analysis ◽

Butt Welding ◽

Effective Selection

The welding process is a nonlinear phenomenon in nature which leads to deformation and residual stresses in weldments. To overcome the structural changes in the weldments the computational packages can be effectively used for analyzing the changes in its life. Inconel superalloys have excellent mechanical properties and are used in the industrial applications. The present simulation is carried out for single pass butt-joint. Simulation studies are used for effective selection of process parameters for improving mechanical properties in the weld structures. In this work, coupled thermo-mechanical simulation process was carried out for predicting the temperatures, distortion and residual stress distribution in the weldments using Finite element analysis at the transverse direction on the welded surface.

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Residual stresses in thermite welded rails: significance of additional forging

Welding in the World ◽

10.1007/s40194-020-00912-4 ◽

2020 ◽

Vol 64 (7) ◽

pp. 1195-1212

Author(s):

B. Lennart Josefson ◽

R. Bisschop ◽

M. Messaadi ◽

J. Hantusch

Keyword(s):

Residual Stress ◽

Stress Field ◽

Residual Stresses ◽

Weld Metal ◽

Welding Process ◽

Surface Zone ◽

Fe Model ◽

Uneven Surface ◽

Residual Stress Field ◽

High Dynamic

Abstract The aluminothermic welding (ATW) process is the most commonly used welding process for welding rails (track) in the field. The large amount of weld metal added in the ATW process may result in a wide uneven surface zone on the rail head, which may, in rare cases, lead to irregularities in wear and plastic deformation due to high dynamic wheel-rail forces as wheels pass. The present paper studies the introduction of additional forging to the ATW process, intended to reduce the width of the zone affected by the heat input, while not creating a more detrimental residual stress field. Simulations using a novel thermo-mechanical FE model of the ATW process show that addition of a forging pressure leads to a somewhat smaller width of the zone affected by heat. This is also found in a metallurgical examination, showing that this zone (weld metal and heat-affected zone) is fully pearlitic. Only marginal differences are found in the residual stress field when additional forging is applied. In both cases, large tensile residual stresses are found in the rail web at the weld. Additional forging may increase the risk of hot cracking due to an increase in plastic strains within the welded area.

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Dynamic Response Analysis of Butt Joint of HTS-A Steel Considering Welding Residual Stresses

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.423-426.944 ◽

2013 ◽

Vol 423-426 ◽

pp. 944-950

Author(s):

Wei Shen ◽

Ren Jun Yan ◽

Lin Xu ◽

Kai Qin ◽

Xin Yu Zhang ◽

...

Keyword(s):

Residual Stress ◽

Dynamic Response ◽

Hot Spot ◽

Time History ◽

High Strength ◽

Simulation Method ◽

Butt Joint ◽

Welding Residual Stress ◽

Response Analysis ◽

Hull Structure

This paper uses both numerical simulation method and experimental research method to study on welding residual stress of high-strength steel of the cone-cylinder hull. Welding is often accompanied by a larger welding residual stress, which directly affects the safety and service life of the hull structure. In order to obtain the distribution of the welding residual stress, the welding procedure was developed by its parameter language by using FE analysis software in this paper. Then the welding residual stress of hot spot region was measured through X-ray nondestructive testing method, and compared it with simulation results. Finally, considering the residual stress as the initial stress, this paper analyzed dynamic response process of the welding structure under combined actions of the welding residual stress and multiaxial loads, which could more accurately determine the stress of welding structure and the location of fatigue risk point. According to the amplitude of damage parameters and strain time-history curve, we can estimate the fatigue life of structure by selecting the corresponding damage models.

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Study on Welding Deformation and Residual Stress of H-Section Beam Based on Finite Element Method

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.753.305 ◽

2017 ◽

Vol 753 ◽

pp. 305-309 ◽

Cited By ~ 1

Author(s):

Xu Lu

Keyword(s):

Mechanical Properties ◽

Residual Stress ◽

Finite Element ◽

Source Parameters ◽

Welding Process ◽

Steel Structure ◽

Bottom Plate ◽

Welding Deformation ◽

Element Simulation ◽

Main Components

The welding H-section beam has good mechanical properties with its superior structure. So they become the main components of steel structure and have been widely used. In this paper, the welded H-section beam is used as the research object. The finite element simulation model is established. The heat source parameters are determined. The deformation of the steel due to the welding process is studied. The results show that the bottom plate and the bottom plate inward bending is about 2.32mm cause by welding process. The residual stress can reach 400MPa.

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