30- credits - Measuring residual stresses in cast iron components

30- credits - Measuring residual stresses in cast iron components

Scania is now undergoing a transformation from being a supplier of trucks, buses and engines to a supplier of complete and sustainable transport solutions.

Ingress

Thesis project at Scania is an excellent way of making contacts for your future working life. Many of our current employees started their career with a thesis project.

Background
Two of the most integral components of Scania’s trucks are the cylinder block and the cylinder head. These components are cast in different grades of cast iron. Casting is the only viable manufacturing option due to the near net shape obtained using this process. Component casting infers a number of interesting challenges. One is the components different section thicknesses which causes uneven solidification and cooling and this can eventually lead to development of residual stresses.

Residual stresses due to the casting process can have a negative influence on the component durability during operation. In certain geometrical conditions residual stresses up to 200-300 MPa (in compacted graphite iron) is possible. The complex nature of development of residual stresses means that both measurement and casting simulation of the phenomena is difficult. During recent development projects, questions regarding residual stresses have been raised. Partly due to new geometry of the components but also due to demands to increase productivity.

Target
The method currently used at Scania to determine residual stresses has shown to give variation in the results. In some cases these results do not align with residual stresses calculated using casting simulation.

The purpose of the current work is to suggest a method to measure residual stresses in the most reproducible way and taking into account the need to be able to measure in difficult to access area of the components.

Assignment
The thesis work will be divided into three parts:
  • Literature study. The aim of this part is twofold. It partly aims to understand the origin and development of residual stresses in cast irons and partly to study and critically review different methods used for residual stress measurements.
  • Experimental work. Cast engine components will be investigated using different methods to measure residual stresses. Focus will be to understand repeatability and accuracy of the methods.
  • Analysis. The analysis part will compare the different methods for residual stress measurements based on the literature study and the experimental work. The aim will be to understand limitations and advantages of different methods and in the end suggest one method or a combination of methods to obtain reliable measurements. A secondary aim is further to analyse and compare experimentally obtained residual stresses with residual stresses simulated by the software Magma for a cast component.
Education
MSc/Civilingenjör in: Materials technology, engineering materials, materials design, solid mechanics, mechanical engineering, Merit: experience from simulation softwares and casting courses
Number of students: 1
Start date: January 2019
Estimated time needed: 20 weeks

Contact persons and supervisors:
Thesis Supervisor: Mathias König, mathias.konig@scania.com, phone: 08 - 553 540 91

Group Manager: Jan Linder, jan.linder@scania.com, phone: 08 - 553 814 65
Mer info
Område Södertälje
Yrkesroll Teknik & Ingenjör, Ingenjör, Civilingenjör
Typ av anställning Heltid, Projekt- / Visstidsanställd
Hemsida http://www.scania.com
Sista ansökningsdag 5 dec (15 dagar kvar)

Om arbetsgivaren

Scania is a world-leading provider of transport solutions. Together with our partners and customers we are driving the shift towards a sustainable transport system. In 2017, we delivered 82 500 trucks, 8 300 buses as well as 8 500 industrial and marine engines to our customers. Net sales totalled nearly SEK 120 billion, of which about 20 percent were services-related. Founded in 1891, Scania now operates in more than 100 countries and employs some 49 000 people. Research and development are concentrated in Sweden, with branches in Brazil and India. Production takes place in Europe, Latin America and Asia, with regional production centres in Africa, Asia and Eurasia. Scania is part of Traton Group. For more information visit www.scania.com.