Correction to: On the effects of austenite phase transformation on welding residual stresses in non-load carrying longitudinal welds

AbstractThe manufacturing of case-hardened gears usually consists of several complex and expensive steps to ensure high load carrying capacity. The load carrying capacity for the main fatigue failure modes pitting and tooth root breakage can be increased significantly by increasing the near surface compressive residual stresses. In earlier publications, different shear cutting techniques, the near-net-shape-blanking processes (NNSBP’s), were investigated regarding a favorable residual stress state. The influence of the process parameters on the amount of clean cut, surface roughness, hardness and residual stresses was investigated. Furthermore, fatigue bending tests were carried out using C-shaped specimens. This paper reports about involute gears that are manufactured by fineblanking. This NNSBP was identified as suitable based on the previous research, because it led to a high amount of clean cut and favorable residual stresses. For the fineblanked gears of S355MC (1.0976), the die edge radii were varied and the effects on the cut surface geometry, hardness distribution, surface roughness and residual stresses are investigated. The accuracy of blanking the gear geometry is measured, and the tooth root bending strength is determined in a pulsating test rig according to standardized testing methods. It is shown that it is possible to manufacture gears by fineblanking with a high precision comparable to gear hobbing. Additionally, the cut surface properties lead to an increased tooth root bending strength.

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[P91] Thermodynamic and Kinetic Modeling of the Ferrite-Austenite Phase Transformation

Calphad ◽

10.1016/j.calphad.2015.01.179 ◽

2015 ◽

Vol 51 ◽

pp. 402

Author(s):

Dong An ◽

Shiyan Pan ◽

Qing Yu ◽

Chen Lin ◽

Ting Dai ◽

...

Keyword(s):

Phase Transformation ◽

Kinetic Modeling ◽

Austenite Phase

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Influence of Phase Transformations on Residual Stresses in Welded Structures

Volume 6B: Materials and Fabrication ◽

10.1115/pvp2013-97684 ◽

2013 ◽

Author(s):

R. J. Dennis ◽

R. Kulka ◽

O. Muransky ◽

M. C. Smith

Keyword(s):

Phase Transformation ◽

Residual Stresses ◽

Phase Transformations ◽

Numerical Models ◽

Material Model ◽

Transformation Model ◽

Austenitic Steels ◽

Beam Specimen ◽

Welded Structures ◽

The Impact

A key aspect of any numerical simulation to predict welding induced residual stresses is the development and application of an appropriate material model. Often significant effort is expended characterising the thermal, physical and hardening properties including complex phenomena such as high temperature annealing. Consideration of these aspects is sufficient to produce a realistic prediction for austenitic steels, however ferritic steels are susceptible to solid state phase transformations when heated to high temperatures. On cooling a reverse transformation occurs, with an associated volume change at the isothermal transformation temperature. Although numerical models exist (e.g. Leblond) to predict the evolution of the metallurgical phases, accounting for volumetric changes, it remains a matter of debate as to the magnitude of the impact of phase transformations on residual stresses. Often phase transformations are neglected entirely. In this work a simple phase transformation model is applied to a range of welded structures with the specific aim of assessing the impact, or otherwise, of phase transformations on the magnitude and distribution of predicted residual stresses. The welded structures considered account for a range of geometries from a simple ferritic beam specimen to a thick section multi-pass weld. The outcome of this work is an improved understanding of the role of phase transformation on residual stresses and an appreciation of the circumstances in which it should be considered.

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Segregation engineering enables nanoscale martensite to austenite phase transformation at grain boundaries: A pathway to ductile martensite

Acta Materialia ◽

10.1016/j.actamat.2013.06.055 ◽

2013 ◽

Vol 61 (16) ◽

pp. 6132-6152 ◽

Cited By ~ 171

Author(s):

D. Raabe ◽

S. Sandlöbes ◽

J. Millán ◽

D. Ponge ◽

H. Assadi ◽

...

Keyword(s):

Phase Transformation ◽

Grain Boundaries ◽

Austenite Phase

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Thermo-mechanical study of single and multi-pass welding of CSEF steel for residual stresses and deformations considering solid state phase transformation

Materials Today Proceedings ◽

10.1016/j.matpr.2019.12.299 ◽

2020 ◽

Vol 28 ◽

pp. 789-795 ◽

Cited By ~ 2

Author(s):

Saurav Suman ◽

Pankaj Biswas

Keyword(s):

Phase Transformation ◽

Solid State ◽

Residual Stresses ◽

Mechanical Study ◽

Solid State Phase Transformation

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Analysis of Ultimate Load-Carrying Capacity of Combined Connection with Bolts and Welds

Mechanika ◽

10.5755/j01.mech.25.6.24791 ◽

2019 ◽

Vol 25 (6) ◽

pp. 426-433 ◽

Cited By ~ 1

Author(s):

Tao LAN

Keyword(s):

Ultimate Load ◽

High Strength ◽

Shear Plane ◽

Deformation Capacity ◽

Load Carrying Capacity ◽

Element Calculation ◽

Lap Splices ◽

Load Carrying ◽

Ultimate Load Carrying Capacity ◽

Longitudinal Welds

In this paper, load-carrying and deformation capacity of tension lap splices that have both welds and bolts acting in the same shear plane are studied using numerical method. The failure criterion of bolts and welds are given based on the finite element calculation and compared with existing experiment results, it shows that the established numerical model is correct and reliable. The strength of longitudinal welds and the bearing capacity of the high-strength bolts before slipping can be fully used in the combined joints, the bolts and welds fail almost simultaneously. The deformation of welds in combined connections is less uniform than its’ deformation in welded joints as the welds fails, and it causes the deformation of welds as failure is larger in combined connections than in welded connections. The deformation capacity of the combined joint are slightly increased contrasted with bolts joint and welds joint because of the interplay of bolts and welds acting in the same shear plane. The strengths of welds and bolts performed in combined connections can reach 0.95 and the deformation of combined connection is increased at least 1.10 times as the welds connection or the bolts connection.

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Finite Element Modelling and Measurements of Residual Stress and Phase Composition in Ferritic Welds

ASME 2010 Pressure Vessels and Piping Conference: Volume 6, Parts A and B ◽

10.1115/pvp2010-25649 ◽

2010 ◽

Cited By ~ 2

Author(s):

Benjamin M. E. Pellereau ◽

Christopher M. Gill ◽

Matthew Dawson ◽

Paul R. Hurrell ◽

John Francis ◽

...

Keyword(s):

Finite Element ◽

Phase Transformation ◽

Residual Stresses ◽

Cyclic Hardening ◽

Tig Welding ◽

Transformation Model ◽

Welding Parameters ◽

Isotropic Hardening ◽

Low Carbon ◽

Fe Modelling

This paper describes finite element (FE) modelling and neutron diffraction (ND) measurements to investigate the development of residual stresses in two different geometries of ferritic weld. All specimens were produced using SA508 Grade 3 steel plates, depositing a low carbon SD3 weld filler by mechanised TIG welding. The FE analyses were carried out using Abaqus/VFT and the behaviour of the SA508 steel was modelled using a simplified (Leblond) phase transformation model with isotropic hardening using VFT’s UMAT-WELD subroutine, which includes the change in volume due to phase transformation. Single bead-on-plate specimens were manufactured using a range of mechanised TIG welding parameters. One pass and three pass groove welds were also produced, in order to investigate the cyclic hardening behaviour of the materials, as well as phase transformation effects in a multi-pass weld. FE analyses were then performed to determine how accurately these effects could be modelled. During manufacture, a number of thermocouples were attached to each of the specimens in order to calibrate the heat input to the FE models. The residual stresses in each of the bead on plate welds, as well as the groove weld after the first and the third passes, were then measured using ND at the middle of the plate. The ND measurements for the three pass weld showed no significant cyclic hardening behaviour although some was predicted by the FE analysis. Another key finding of the FE modelling that was seen in all of the models was that the phase transformation acts to reduce the stress levels in the deposited weld metal leaving the largest tensile stresses in a ring at the outer edge of the full heat affected zone (HAZ). There are plans to refine the FE studies using improved material properties when material testing of SA508 and SD3 are completed in the near future.

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