Student News

ASM Heat Treating Society 2011 Conference and Exhibition

One of our graduate students,Yingying Wei received the 2011 HTS/Bodycote Best Paper Award for her paper titled “Intelligent Heat Treating: Simulation of Carburization Process”. The award has been presented by Dan McCurdy, president of Automotive and Commercial Heat Treat at Bodycote, at the HTS General Membership Meeting on Nov. 1, 2011, during the HTS Conference and Exposition in Cincinnati, Ohio.

The meeting was held on October 31- November 2, 2011 in Cincinnati, Ohio.

Professors:
Richard D. Sisson,Jr., Diran Apelian, Makhlouf Makhlouf

Post Doctorate Students:
Liang He

Graduate Students:
Yuan Xu, Danielle Belsito, Mei Yang, Lei Zhang, Yingying Wei, X. Wang, Chang-Kai Wu

Papers Presented:

Presentations Given:

  • Precipitation evolution and strength prediction of Al alloys
  • A Process Model for Carbonitriding of Steel
  • Modeling of Microstructural Development During the Nitriding of Low Alloy Steels
  • Austenite Grain Growth

Intelligent Heat Treating: Simulation of Carburization Process

Authors:

Yingying Wei, G. Wang, R.D. Sisson, Jr., B. Bernard, and R. Poor

Abstract: Heat treaters need an effective simulation tool to predict the carburization performance of a variety of steels. The tool is needed not only to predict the carbon profile but also to optimize the process in terms of the cycle time and the cost. CarbTool© has been developed to meet these needs for gas and vacuum carburization. In this paper, CarbTool© predictions were compared with the industrial experimental results of four types of steels, heat treated by both gas and vacuum carburizing processes. Based on the excellent agreement of model predictions ad experimental results, Carbtool may be used to predict the carbon concentration profile for a variety of alloys in both gas and vacuum carburizing processes.

Evaluation of process control methids for nitrogen-hydrocarbon atmospheres

Authors:

Xiaolan Wang; Zbigniew Zurecki; and Richard D. Sisson, Jr.

Abstract: Atmospheric pressure carburizing and neutral carbon potential annealing in nitrogen containing small additions of hydrocarbon gases can offer cost and steel surface quality alternatives to the comparable, endothermic atmosphere or vacuum operations. An experimental program was conducted for refining real-time process control methods in carburizing of AISI 8620 steel under N2-C3H8 blends containing from 1 to 4 vol% of propane at 900℃ and 930℃. Multiple types of gas analyzers were used to monitor residual concentrations of H2, CO, CO2, H2O, O2, CH4, C3H8, and other hydrocarbons inside furnace. A modified shim stock technique and the conventional oxygen probe (mV) were additionally evaluated for correlation with gas analysis and diffusional modeling using measured carbon mass flux values (g/cm2/s). Results of this evaluation work are presented.

Development of Low-Cost, Rapid Case Hardening Treatments for Austentic Stainless Steels

Authors:

Xiaolan Wang; Zbigniew Zurecki; and Richard D. Sisson, Jr.

Abstract: Austenitic stainless steels are critical in the modern economies with applications ranging from food processing and cryogenic machinery to medical implants and aerospace instrumentation. Tough, resistant to low-temperature embrittlement and many forms of corrosion, these steels are, nevertheless, prone to scratching and galling in service. Case hardening was found to be effective when combined with corrosive surface treatments or in low-pressure, direct plasma-ion discharges, but inhibited in simple atmospheric-pressure furnaces. This paper presents preliminary evaluation of new, rapid (3-4 hrs) nitriding and carbonitriding treatments at low- (500-565℃) and high- (1100℃) temperature ranges involving injection of high-voltage, electric arc-activated, N2-based, NH3 and hydrocarbon gas mixes to the conventional box furnace. Reported data includes characterization of stainless steel product layers using SEM-EDS, XRD, OM, Leco elemental analysis, and microhardness profiling, as well as laser gas analysis of the residual furnace atmosphere.

November 3, 2011