Promoting ductility and formability in a carbide free bainitic steel via pre-annealing treatment

N Xu, L Wang, J Hu, Z Chai, W Zhao, W Xu - Materials Characterization, 2023 - Elsevier
This study aimed to overcome the existing trade-off in strength–ductility in carbide free
bainitic steel and improve ductility without compromising strength. Herein, we proposed a …

[HTML][HTML] In-situ SEM characterization and numerical modelling of bainite formation and impingement of a medium-carbon, low-alloy steel

O Seppälä, A Pohjonen, J Mendonça, V Javaheri… - Materials & Design, 2023 - Elsevier
A novel in-situ scanning electron microscope (SEM) characterization technique for
observing phase transformation is developed and its results studied and compared to well …

[HTML][HTML] Coupled model for carbon partitioning, diffusion, Cottrell atmosphere formation and cementite precipitation in martensite during quenching

A Pohjonen, SR Babu, VV Visuri - Computational Materials Science, 2022 - Elsevier
High-strength low alloy martensitic alloy steels are produced by quenching methods to
achieve a martensitic microstructure. The carbon supersaturation of the martensitic structure …

Full field model describing phase front propagation, transformation strains, chemical partitioning, and diffusion in solid–solid phase transformations

A Pohjonen - Advanced Theory and Simulations, 2023 - Wiley Online Library
A novel mathematical formulation is presented for describing growth of phase in solid‐to‐
solid phase transformations and it is applied for describing austenite to ferrite transformation …

Solving partial differential equations in deformed grids by estimating local average gradients with planes

A Pohjonen - Journal of Physics: Conference Series, 2021 - iopscience.iop.org
For constructing physical science based models in irregular numerical grids, an easy-to-
implement method for solving partial differential equations has been developed and its …

Evaluation of a processing route and microstructural characteristics for the development of ultrafine bainite in low-temperature ausformed medium-carbon steels

P Kaikkonen, MC Somani, A Pohjonen… - Journal of Materials …, 2023 - Springer
A combination of physical simulation and laboratory rolling experiments, including
thermomechanical rolling and low-temperature ausforming, was conducted for designing a …

Gradient Boosted Regression Trees for Modelling Onset of Austenite Decomposition During Cooling of Steels

J Luukkonen, A Pohjonen, S Louhenkilpi… - … Materials Transactions B, 2023 - Springer
Continuous cooling transformation (CCT) diagrams can be constructed by empirical
methods, which is expensive and time consuming, or by fitting a model to available …

Effect of forging sequence and heat treatment on microstructure of high-duty power-plant shaft made of Cr-Mo ultra-high strength steel

P Skubisz, L Lisiecki - Journal of Mining and Metallurgy, Section …, 2023 - aseestant.ceon.rs
The paper presents the results of modeling and testing of a heavy weight part made of Cr-
Mo, which was V-modified ultra-high strength steel grade AISI 4140, processed through a …

Numerical simulations of gradient cooling technique for controlled production of differential microstructure in steel strip or plate

A Pohjonen - 2021 - oulurepo.oulu.fi
Numerical studies were conducted to investigate the applicability of cooling strategies for
controlledly producing a microstructure in the steel strip or plate, which changes as function …

Application of two-grid interpolation to enhance average gradient method for solving partial differential equations

A Pohjonen - Journal of Physics: Conference Series, 2024 - iopscience.iop.org
Previously presented method of calculating local average gradients for solving partial
differential equations (PDEs) is enhanced by using interpolating gridpoints and triangular …