Abstract
Effect of soot on wear of valve and valve sheet insert is investigated under the dry and lubricated conditions. Specimens used are stelite#12 for valve, SUH3 and three kinds of Fe base sintered alloys for valve sheet insert. Experiments are conducted with three types of test. One is a crossed cylinder point contact impact-sliding wear test for basic test. The other two are the tests using actual valve and valve sheet insert, that is, an impact test and a micro slip test induced by explosion force. The main results are as follows. (1) Under the dry condition, soot between the contacting surfaces decreases wear of seating surfaces. (2) Under the lubricated condition, soot increases the wear compared to the lubricating oil without soot. (3) Agglomerated soot has a load carrying capacity and makes seating surfaces deform plastically.
