Master Thesis: Model for Adjusting the Bar Straightening Process to Minimize Residual Stresses

What do you get?

You will be a part of a company doing the right thing because its right, that already today has a world-leading CO2 position and is doing its best to create a sustainable society.

Ovako is an employer for you who likes the smaller organizations efficient decisions and the larger organizations security. At Ovako you can expect an energetic and forward-leaning place of work, with open discussions, good camaraderie and great organizational drive. As an employee you get (among other things)

• A workplace with focus on employee health, safety and wellbeing
• Great personal responsibility and freedom to how you solve your tasks
• A culture that likes to be challenged and welcomes new ideas that improves
• Ability to work in a dynamic environment with engaged and experiences coworkers

Backgrund and purpose

Steel bars used in various industrial applications must be as straight as possible to ensure their quality. However, when the bars are straightened using straightening machines, residual stresses can occur, especially if the machine is not properly calibrated. These stresses can negatively affect the material's grain stability, resulting in a weakened product. Currently, there is a lack of theoretical knowledge about how to correctly adjust the straightening machines to avoid such issues. This has led to recurring problems with residual stress in steel bars delivered to customers.

This project aims to address this gap by developing a model to guide the proper setup of straightening machines. The ultimate goal is to achieve the straightest possible bars while controlling and minimizing residual stresses.

Description

This thesis will involve the development of a theoretical and practical model to help set up steel straightening machines to minimize residual stress. The candidate will investigate the relationship between machine settings (e.g., applied force, roll angles and position) and the resultant residual stress in the steel bars. The project will focus on creating a balance between achieving the straightest bars and minimizing residual stresses, which impact the long-term grain stability and mechanical properties of the steel.

The thesis will also explore the limits of how much force can be applied to the steel bars without causing defects, such as end hooks or excessive residual stress. By the end of the project, the candidate will deliver a model that can be used in production to adjust the straightening machines for optimal performance.

Research question

• How should a reel straightening machine be set up to achieve the straightest bars possible?
• What is the relationship between applied straightening force, roll angles, roll position and the resulting residual stress in the bars?
• How can we optimize the straightening process to improve grain stability?
• What are the indicators of high residual stress, and how do they affect steel bar quality?

The expected outcome is a model that will provide guidelines for setting up straightening machines, ensuring minimal residual stress and defects while maximizing bar straightness.

About the team

The candidate will work closely with the production team at Ovako, including machine operators, process engineers, and metallurgists, to gather data and test the developed model. There may also be opportunities to conduct on-site visits and tests to validate the model in real production environments.

Project setup

This thesis will involve both theoretical modeling and practical testing. Depending on the progress of the model's development, the candidate may be involved in testing the model on actual machines at Ovako's production facility. The project is expected to be conducted in collaboration with the development department.

If you have any questions, you are most welcome to contact Ovako’s Representative as Supervisor:

Oscar Modigs 

Email: oscar.modigs@ovako.com

Your profile

Mechanical Engineering Materials Science Physics (with a focus on applied mechanics)

Other required skills:

Basic knowledge of materials deformation and mechanics Experience with mathematical modeling and simulation tools (e.g., MATLAB, ANSYS, or similar) Problem-solving and analytical thinking Ability to work with production teams and understand industrial machinery 

Information & other

Compensation

Ovako will compensate you for completed master thesis corrsponding to a value per "högskolepoäng". We can also in most cases assist with accomodation during the time you are performing your master thesis with us. Ovako will support with travel to and from our sites for interviews, eventual trips back to the university for meetings with supervisor and equivalent.

Recruitment

Selection will be ongoing and during the process you will get the chance to meet potential supervisors, relevant managers and stakeholder. The process will include ability tests, interviews, background check and references.