Effect of 316L Steel Variation on Forming of Steel Pieces - and can it be compensated for?

Abstract

As for now, there is a need for more information and understanding about how variations in 316L steel affect the deformation of sheet steel to produce steel pieces. Therefore, this project aims to present the material's variation regarding chemical composition, mechanical properties and coil dimensions. Furthermore, experiments are conducted to evaluate the quality of deformed steel pieces and identify any effect resulting from variation in the steel material. In this project, the steel has been analysed in LOM and EBSD to investigate its microstructure. Other analytical methods used are ICP-OES, XRF and combustion to detect the chemical composition of the steel. Lastly, several different deformations experiments were conducted to evaluate the effect of variations in the steel on the finished deformation and size of the steel pieces. The results showed no significant differences in the microstructure of the steel or the deformation or size of the produced steel pieces depending on the subsuppliers. Moreover, it revealed no differences within coils regarding coil thickness or in the deformation or size of the produced steel pieces. It also showed that steel with higher yield strength and thickness gives a lower deformation value, but the deformed steel piece's length and width were unaffected. Using a higher force will result in a steel piece with more extensive deformation and a smaller range without introducing more defects. Dwell time did not affect the results of the deformation or size of the steel piece.

Popular Abstract

The first known production of steel dates back 4000 years ago in the form of ironware in the region of today's Turkey. Since then, steel usage has exploded and is today the most essential engineering and construction material. It is still used today because it is an essential material in society, and the constant development of the materials makes it fit for modern functions. This study aims to deepen the understanding of steel's behaviour to optimise its full potential and establish its future usage. More precisely, the study has focused on the effect of 316L steel variations on the forming of steel pieces and has the goal of giving recommendations to the production of how the settings in the deformation machine may compensate for the variations.

Many factors have to be considered before having a complete understanding and control over how a steel piece is deformed. The outcome of the deformed piece can be affected by the type of machine, deformation tools or setting used. However, even more interesting, the steel's properties will impact the steel's forming. To produce steel products with high quality, an understanding of the properties of the steel and how variations of these may affect the finished product is crucial. This is because, without this knowledge, the outcome of the deformation may vary between different steel, leading to irregular production.

The different variations that have been studied are the yield strength, microstructure and composition of the steel, along with the thickness of the steel coil. We could conclude from the results that steel with higher yield strength and thickness generally gave steel pieces with lower deformation. Beyond this, the usage of higher forces is also seen to be beneficial to all steels since it gives a lower range of deformation, leading to more uniform steel pieces without introducing more defects. Another exciting discovery was the variation in grain size between the studied steels. We could see that this steel property appears influential since the steel with a significantly smaller grain size also behaved differently than all other steels in the production.

The recommendation that can be made to the production from this study is to use a higher force if a lower range of deformation is desired. Furthermore, the settings in the deformation machine can compensate for steel with high thickness and yield strength by using a higher force to achieve the same deformation as steel with low values.

This study has only covered some variables that can affect the deformation of steel. Understanding the most influential properties when deforming it needs to be further analysed. It is vital to continue the development and increase the understanding of the material to ensure the usage of steel. Who knows, 4000 years into the future, steel is still one of our most essential materials?

• author: Jigsved, Tilda and Gillberg Strandberg, Ronja
• supervisor: Martin Ek
• organization: Centre for Analysis and Synthesis
• course: KASM10 20231
• year: 2023
• type: H2 - Master's Degree (Two Years)
• subject: Chemistry
• keywords: deformation, steel, 316L, materials chemistry
• language: English
• id: 9121236
• date added to LUP: 2023-07-11 08:39:35
• date last changed: 2023-07-11 08:39:35