Continuous Sinter Cooling Transformation Diagram Technical Publications
156. Development of a High Performance Nickel-Free PM Steel: A developmental nickel-free PM steel containing Cr, Mn, Si and Mo is being evaluated as a new high performance material. Bonded premixes with varying carbon contents were made with the AncorMax® D system and pressed to densities of 7.2 g/cm3. Sintering studies were performed at 1177°C and 1260°C. Higher strengths were achieved in the CrMnSiMo steel as compared to a Ni containing steel with a higher total alloy content. Ultimate tensile strengths over 1200 MPa and hardnesses of 70 HRA can be achieved in the sinter + temper condition. The effect of sintering temperature, cooling profile and carbon content on mechanical properties and microstructure will be discussed.
154. A Review of Current Sinter-Hardening Technology: Sinter-hardening has developed into a highly cost effective production method for the production of through hardened PM parts without the need for additional heat-treatments. Over the last several years advances have been made in sinter-hardening material systems and furnace technology. This paper reviews these advances as well as some key processing parameters required to produce high quality sinter-hardened components. Specific topics included are proper alloy selection, mechanical and fatigue properties, microstructural development, optimization of furnace cooling rates, and proper tempering practices.
141. Effects of Cooling Rate on the Hardenability of Chromium Containing PM Steels: Two chromium containing grades, Cr-modified Ancorloy® MDC and a developmental CrMnSiMo steel, have been investigated to develop an understanding of the phase transformation behavior of these steels during cooling. The cooling rates studied are in the range typically found in sintering furnaces. A quantitative study to assess the hardenability of these materials has been undertaken and the results of dilatometric, metallographic and hardness evaluations to determine the effects of cooling rate on the various Cr containing steels are presented.
134. Ancorloy® Hardenability: The Continuous Sinter Cooling Transformation diagrams of five proprietary admix compositions including Ancorloy® 2 and Ancorloy® 4 at sintered carbon contents of 0.50 w/o and Ancorloy® MDB, Ancorloy® MDC and Ancorloy® MDCL at sintered carbon contents of 0.60 w/o are presented for sintered densities in the neighborhood of 7.10 g/cm3.
119. Cooling Rate Effects on the Metallurgical Response of a Recently Developed Sinter Hardening Grade: The results of dilatometric, metallographic and hardness determinations to characterize the effects of cooling rates in the low to moderate sinter hardening range on the response of various Ancorsteel® 737 SH compositions are presented.