Contact fatigue testing of camring steel
2010 (English)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
Student thesis
Abstract [en]
The aim of the present thesis work was to establish a fatigue-test setup and perform several tests to characterize different combinations of steels and heat treatments. These materials should be suited for usage as cam ring material in hydraulic drives. Carring out the tests in a short time was one of the main features for the selection of the test-method. For characterizing the materials the Standing Contact Fatigue method was choosen. In this method, the sample is pressed against a hard ball in rapid succession causing different types of cracks in the contact-zone. The contact area was inspected after each test. Since a continuation of a performed test is not possible, a following test was carried out with more or less cylces, depending on the previous result (cracks found or no cracks present). In addition, a strain-gauge set-up was established for testing an insitu crack detection. Mostly ring-cone cracks were found at the edge of the indentation but inside the indent. The sectional view shows, that these crack grow underneath the indentation. The tests, performed at 60 Hz and a load cycle between 500 N and 15 kN, show a higher fatigue limit for the samples tempered at 240°C than the samples at 180°C. The highest fatigue limit was tested for the electro slag remelted steel tempered at 240°C.
Place, publisher, year, edition, pages
2010.
Keywords [en]
Technology, Standing Contact Fatigue (SCF), fatigue tests, electro slag, remelted (ESR) steel, heat treatment, strain gauge
Keywords [sv]
Teknik
Identifiers
URN: urn:nbn:se:ltu:diva-46088ISRN: LTU-PB-EX--10/005--SELocal ID: 3b9d94e3-d7ca-4768-a98f-f22cb167f374OAI: oai:DiVA.org:ltu-46088DiVA, id: diva2:1019400
Subject / course
Student thesis, at least 30 credits
Educational program
Materials Engineering, master's level
Examiners
Note
Validerat; 20101217 (root)
2016-10-042016-10-04Bibliographically approved