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A D V A N C E D M A T E R I A L S & P R O C E S S E S | F E B R U A R Y / M A R C H 2 0 1 7

5 6

Eighteen years ago, the Center for Heat Treating Ex-

cellence (CHTE) was founded with the goal of bringing the

industrial sector and university researchers together to

find solutions to real-world problems. Today, CHTE—locat-

ed at Worcester Polytechnic Institute (WPI) in Massachu-

setts—has 19 members from all areas of industry working

together with WPI researchers to improve both heat treat

and thermal processing methods worldwide.

The organization has an impressive body of work.

It has completed more than 20 projects that cover every-

thing from induction tempering, thermal processing, and

distortion to gas and oil quenching, energy efficiency de-

termination, furnace modeling, alloy life extension, gas

and vacuum carburization, and more.


CHTE’s latest project is called “Guidelines for Assess-

ing Distortion and Residual Stress.” According to Richard

Sisson, George F. Fuller Professor of Mechanical Engineer-

ing and CHTE technical director, this is an area of huge con-

cern; companies spend millions of dollars scrapping parts

that become distorted during the heat treat process, in ei-

ther the heating or cooling period. Further, some materials

have stored residual stress, which causes distortion and

compromises part integrity.

Steve Ferdon, director of engineering technology in

the fuel systems business at Cummins Inc., and current

chair of CHTE’s board of directors, is excited about this

project. “Because residual stress and heat treat distortion

are recurring frustrations for the industrial membership,

we have had a truly open and collaborative effort to devel-

op the scope of work for this project,” says Ferdon. “Global

players in the aerospace, industrial equipment, transpor-

tation, automotive, heat treat equipment, and integrated

computational materials engineering (ICME) industries are

engaged and will provide technical guidance and resourc-

es throughout the project. The expected outcome will be

development of precompetitive data, process design prac-

tices, and analytical tools that will have a real, practical,

and immediate benefit to members’ bottom lines.”

Key project objectives include:

1. Determining the most important heat treating

process parameters that impact residual stress

and distortion in industrial parts.

2. Developing a ranking of these processing

parameters based on their impact.

3. Providing processing guidelines to control

residual stress and distortion.

This is a big undertaking for CHTE. The center is now

compiling a list of parameters to start putting boundaries

on the project, which will further refine the scope. Currently,

the project is in the modeling and simulation phase with the

expectation that research testing will begin in June (Fig. 1).


What makes CHTE unique from other collaborative

efforts is that members select the research projects. In

December 2016, CHTE andWPI researchersmet todetermine

the direction of additional studies. Based on their input, the

project selection committee determined that many compa-

nies are facing similar areas of concern, thus defining key

topic areas that the center is considering for future research:

Processing modeling and data validation

is of key

importance. This aligns well with the ATC TMI road

map that was sponsored by NIST and ASM Interna-

tional and published in 2015. In this roadmap, a

significant focus is developing tools for simula-

tion. CHTE has two member companies—Thermo

Calc and DANTE Solutions—that both focus on ICME,

and this is becoming more important as a tool to

understand complex material systems before

investing in expensive physical models, prototypes,

or processes. Many of the CHTE studies will contrib-

ute to the datasets available for ICME studies.


is an emerging topic of interest among the

membership. OEMs desire a better understanding

Fig. 1 —

Cylinders of several steel grades were austenitized and

quenched in water. The residual stress in hoop direction as pre-

dicted by DANTE, (a) Pyrowear53, (b) AISI 4140 steel, and (c) AISI

52100 steel. Compressive stress in the hoop direction developed

in the exterior part for Pyrowear53 and AISI 4140 steel. Tensile

stress developed in the 52100 steel. Variation is due to differences

in martensite start temperature.