Thermal stress history in high-tensile strength steels during weld process

2004 ◽  
Vol 120 ◽  
pp. 635-648
Author(s):  
M. Mochizuki ◽  
M. Toyoda
Keyword(s):  
Residual Stress ◽  
Tensile Strength ◽  
Phase Transformation ◽  
Thermal Stress ◽  
Stress Generation ◽  
Experimental Result ◽  
High Tensile Strength ◽  
Stress History ◽  
Fundamental Study ◽  
History Of

Thermal and residual stresses in High-Tensile Strength Steels during weld process are numerically simulated considering phase transformation effect. Fundamental study for the history of thermal stress due to phase transformation and residual stress during welding heat cycles is studied in order to investigate the generating mechanism of residual stress and the effects of material properties on stress generation. Two materials of high-tensile strength steels are used in the numerical simulation and experiment. Material property of each microstructural phase is used and the time- and temperature-dependant proportion of microstructure are considered by using CCT-diagram in the analysis. Thermal stress history obtained by the simulation agrees well with the experimental result during welding heat cycles. Some applications to repair welds and fillet-weld joints of the analytical method are then introduced.

Generation Behavior of Thermal and Residual Stresses Due to Phase Transformation During Welding Heat Cycles

2002 ◽  
Author(s):  
Masahito Mochizuki ◽  
Shogo Matsushima ◽  
Masao Toyoda ◽  
Zhiliang Zhang ◽  
O̸yvind Gundersen ◽  
...  
Keyword(s):  
Residual Stress ◽  
Phase Transformation ◽  
Thermal Stress ◽  
Material Properties ◽  
Stress Generation ◽  
Experimental Result ◽  
High Tensile Strength ◽  
Weld Residual Stress ◽  
History Of ◽  
Simulation And Experiment

Weld residual stress is possible to be controlled by considering and changing mechanical properties of the materials. History of thermal stress due to phase transformation and residual stress during welding heat cycles is studied in order to investigate the generating mechanism of residual stress and the effects of material properties on stress generation. Two materials of high-tensile strength steels are used in the numerical simulation and experiment. Material property of each microstructural phase is used and the time- and temperature-dependant proportion of microstructure are considered by using CCT-diagram in the analysis. Thermal stress history obtained by the simulation agrees well with the experimental result during welding heat cycles.

A Study of Delamination Mechanism of Thermal Barrier Coating under Thermal Cycling and Aging Condition by Residual Stress History

2009 ◽  
Vol 417-418 ◽  
pp. 173-176
Author(s):  
Hiroyuki Waki ◽  
Akira Kobayashi
Keyword(s):  
Residual Stress ◽  
Thermal Stress ◽  
Thermal Cycling ◽  
Thermal Aging ◽  
Ceramic Coating ◽  
Plane Surface ◽  
Diffraction Method ◽  
Thermal Barrier ◽  
Stress History ◽  
Bond Coating

Thermal barrier coatings (TBCs) have been employed for the insulation of substrates from high temperature in gas turbine plants. The TBC system consists of ceramic top coating, metallic bond coating and substrate. Delamination of the ceramic coating is important problem in TBC systems. In this paper, the delamination mechanism was studied by residual stress history under thermal aging and thermal cycle conditions. In-plane residual stress histories of ceramic coating and bond coating after thermal aging and cycling were measured by X-ray diffraction method. The residual stress under thermal cycling was also calculated by FEM analysis. The results obtained were as follows: (1) in-plane surface residual stresses of the coatings scarcely changed regardless of the increase of thermally grown oxidation (TGO). (2) high compressive thermal stress, residual stress at room temperature, in ceramic coating induced by thermal stress did not occur. It was found that stress of ceramic top coating was relaxed by micro cracks and driving stress of delamination was in-plane high compressive stress.

scholarly journals Residual Stress Evaluation of Butt Weld Sample of High Tensile Strength Steel Using Neutron Diffraction

2005 ◽  
Vol 54 (7) ◽  
pp. 685-691 ◽  
Author(s):  
Hiroshi SUZUKI ◽  
Thomas M. HOLDEN ◽  
Atsushi MORIAI ◽  
Nobuaki MINAKAWA ◽  
Yukio MORII
Keyword(s):  
Residual Stress ◽  
Tensile Strength ◽  
Neutron Diffraction ◽  
High Tensile Strength ◽  
Butt Weld ◽  
Stress Evaluation

CARTECH MP35N

Alloy Digest ◽  
2021 ◽  
Vol 70 (3) ◽  
Keyword(s):  
Tensile Strength ◽  
Corrosion Resistance ◽  
Phase Transformation ◽  
Heat Treating ◽  
Unique Combination ◽  
High Tensile Strength ◽  
Excellent Corrosion Resistance ◽  
Technology Corporation ◽  
Carpenter Technology Corporation ◽  
Hardened Condition

Abstract CarTech MP35N is a wrought Co-Ni-Cr-Mo alloy that possesses a unique combination of ultra-high tensile strength (up to 2070 MPa, or 300 ksi), good ductility and toughness, and excellent corrosion resistance. The unique properties of CarTech MP35N are developed through work hardening, phase transformation, and aging. If the alloy is used in the fully work hardened condition, service temperatures up to 400 °C (750 °F) are suggested. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Co-134. Producer or source: Carpenter Technology Corporation.

scholarly journals Effect of Phase Transformations on Scanning Strategy in WAAM Fabrication

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7871
Author(s):  
Muhammad Hassaan Ali ◽  
You Sung Han
Keyword(s):  
Residual Stress ◽  
Additive Manufacturing ◽  
Residual Stresses ◽  
Phase Transformations ◽  
Manufacturing Industry ◽  
Welding Process ◽  
Stress Generation ◽  
Temperature History ◽  
History Of ◽  
Wire Arc Additive Manufacturing

Due to its high production rates and low cost as compared to other metal additive manufacturing processes, wire arc additive manufacturing (WAAM) has become an emerging technology in the manufacturing industry. However, the residual stress generation and part distortion hinder its widespread adoption because of the complex thermal build-histories of WAAM parts. One of the ways to alleviate this problem is to consider the effects of scan strategies as it directly influences the thermal history of the built part. Since WAAM itself is an evolved welding process and even though it is evident from welding studies that phase transformations directly affect the residual stresses in welded parts, it remains unclear how the consideration of phase transformations for different scan strategies will affect the residual stresses and distortions in the WAAMed parts. A FEM study has been performed to elucidate the effects of phase transformations on residual stresses and the distortion for different deposition patterns. The current findings highlight that for the fabrication of low-carbon martensitic steels: The consideration of phase transformations for line-type discontinuous patterns (alternate and raster) do not significantly affect the residual stresses. Consideration of phase transformations significantly affects residual stresses for continuous patterns (zigzag, in–out and out–in). To accurately simulate complex patterns, phase transformations should be considered because the patterns directly influence the temperature history of the built part and will thus affect the phase transformations, the residual stresses and the warpage. During the fabrication of WAAM parts, whenever possible, discontinuous line scanning patterns should be considered as they provide the part with uniform residual stress and distortion. The alternate line pattern has been found to be the most consistent overall pattern.

Numerical Simulation of Welding Residual Stress Considering Phase Transformation Effects

2011 ◽  
Vol 295-297 ◽  
pp. 1905-1910 ◽  
Author(s):  
Hai Zhang ◽  
Dong Po Wang ◽  
Sen Li
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Phase Transformation ◽  
Volume Change ◽  
Weld Zone ◽  
Thermal Strain ◽  
Welding Residual Stress ◽  
Different Temperatures ◽  
History Of ◽  
Welding Processes

The welding processes of steel materials are often accompanied by the occurrence of phase transformation. Volume change caused by phase transformation will affect the history of stress and strain. In this article, taking the welding of Q345 as an example, the effects of solid-state phase transformation on the residual stress were investigated by numerical simulation. The values of thermal strain at different temperatures were set to make the volume change caused by phase transformation equivalent as thermal strain. The simulation contained two cases both considering phase transformation and not. The results show that in both two cases the longitudinal stress distribution in the weld zone has almost the same trend. But in the case without considering phase transformation, there is large longitudinal tensile stress concentrating in the weld and HAZ zone and the maximum value is up to 427MPa in the weld. For transverse stress, phase transformation not only changes the value of the stress, but also alters the sign of the stress in the middle of the weld zone. Experiment was also carried out to measure the residual stress by X-ray diffraction. The result considering phase transformation matched much better with the experimental data. It can be concluded that phase transformation in the process of welding has a significant effect on the residual stress and can not be ignored in the numerical simulation of welding.

Present Situation and Prospect of Residual Stress Modelling Technology in Metal Cutting

2014 ◽  
Vol 800-801 ◽  
pp. 601-606
Author(s):  
Wei Zhang ◽  
Xiao Liang Cheng ◽  
Min Li Zheng ◽  
Zhao Xing Zhang ◽  
Shu Qi Wang
Keyword(s):  
Residual Stress ◽  
Phase Transformation ◽  
Thermal Stress ◽  
Stress State ◽  
Mechanical Stress ◽  
Metal Cutting ◽  
Mutual Influence ◽  
Present Situation ◽  
Type Size ◽  
External Loads

Residual stress ,with the branch of type, size and direction, is defined as the stress state which exists in a body after all the external loads are removed [1].According to the mutual influence scope size,residual stress can be divided into macroscopic residual stress and micro residual stress. Cutting residual stress is mainly caused by mechanical stress, thermal stress and phase transformation.

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