Werkstoffeigenschaften nach besonderer Wärmebehandlung

FKM 1995 Project No. 198
Final report
Abstract:

The short project "Standardization of specimens for vibration tests" was carried out as a questionnaire campaign. The questionnaire was designed to obtain comprehensive information on the specimen forms currently in use. Particular importance was attached to the question of existing experience with the respective specimen forms. In most cases, the data obtained is reproduced in the report without comment. For example, information on the shape number Kt and its determination was missing in some cases. However, shape numbers differ considerably depending on the determination method. Overall, the question about the experience gained with the samples was only answered unsatisfactorily. On the one hand, this may be due to the fact that certain necessities are taken for granted when carrying out vibration tests and, on the other hand, an understandable reluctance to answer this question when unfavorable experience is available. The questionnaires received dealt exclusively with the specimen forms material specimen (smooth round bar, smooth flat bar, incl. LCF specimens) and notched bar as a component-like specimen. The majority of all questionnaires provided data on LCF specimens. For material tests on smooth specimens in stress or strain-controlled tests, the specimen shape developed by IABG with a radius sequence to simulate the transition from the clamping end to the test cross-section, in which the test length itself is formed by a large radius, was recommended. With this specimen shape, a shape number Kt = 1.0 is achieved. Breaks in the transition area were almost always avoided. Free-form transitions, which can be derived using the GAG method (Computer Aided Optimization) in conjunction with FE analyses, lead to the same results. However, as sample quality and production costs are generally in competition, the choice of sample remains a case-by-case decision. The existing testing machines and fixtures, the costs of specimen production depending on the number of specimens and the necessary measurement technology are some of the determining factors. This report therefore makes recommendations and outlines strategies that are based on existing experience and are intended to standardize specimens in the field of fatigue strength. However, this can only succeed on the basis of the broadest possible acceptance by the companies and institutes involved. Scope of report: 40 pages of text including pictures and tables, 101 specimen forms Start of work: 01. 01. 1995 End of work: 31.12.1995 Funding body: FKM own funds Research center: Institute for Mechanical Plant Engineering and Structural Durability (lfB) Clausthal University of Technology (TUC) Head: Prof. Dr.-lng. H. Zenner Author: Dr.-lng. H. Buschermöhle (lfB) Chairman of the working group: Dr.-lng. C. Gerdes, ABB Kraftwerke AG, Baden Dipl.-lng. M. Lüdeke, Audi AG, Ingolstadt Chairman of the Advisory Board: Prof. Dr.-lng. H. Kipphan, Heidelberger Druckmaschinen, Heidelberg Project No. 135 Material properties after special heat treatment {short-time nitriding} Final report (Volume 2)
Abstract:
The subject of the present investigation is the experimental determination of the pure material properties as they exist in the different edge distances of induction surface hardened components. Monotonic and cyclic characteristic values of the material variants 100 Cr 6 GKZ, 42 CrMo 4 V, 44 MnSiVS 6 BY and Ck 45 N were investigated after various short-term austenitizing and tempering treatments. The material properties were determined on smooth, thin, cylindrical samples in whose sample volume a temporally and spatially homogeneously austenitized microstructure in a largely residual stress-free state was present after temperature-controlled induction heating. The variation of the austenitization conditions (15 -17 per material variant) was carried out by selecting different parameter combinations of austenitization temperature and duration. Extensive X-ray graphical and metallographic investigations of the microstructures were also carried out. In the following, the dependence of the pure material properties on the austenitization conditions present during short-term austenitization for the four investigated materials is presented in detail for the first time. The presentation includes image series of light and scanning electron micrographs of the microstructures and fracture surfaces.

Scope of report:
412 p., 362 ill., 9 lit. (3 vols.)
Start of work:
01.07.1989
End of work:
30. 06. 1995
Funding body:
AVIF-No. A33
Research unit:
Institut für Werkstoffkunde, Technische Hochschule Darmstadt
Head:
Prof. Dr.-lng. K.H. Kloos
Author:
Dr.-lng. P. Braisch Dipl.-lng. J. Rollmann
Chairman of the working group:
Dr.-lng.lng. H. Schlicht and Dr.-lng. H.-W. loch FAG Schweinfurt
Chairman of the Advisory Board:
Prof. Dr.-lng. H. Kipphan Heidelberger Druckmaschinen AG, Heidelberg