ORIGINAL ARTICLE
Heuristic design of U-shaped die cooling channel for producing
ultra-high strength steel using hot press forming
Mohd Fawzi Zamri
1
&
Ahmad Razlan Yusoff
1
Received: 5 January 2018 / Accepted: 30 April 2018
#
Springer-Verlag London Ltd., part of Springer Nature 2018
Abstract
This paper proposes an optimised cooling channel design for a U-shaped die in the hot sheet metal forming process using a
heuristic method. Unlike in previous works, the parameters used in this study for optimising the cooling channel design not only
consider the pitch between and diameter of cooling channels but also their distance from the tool surface and wall tool. The
cooling channel design is optimised by coupling the heuristic method with finite element thermal and static analyses. The main
factors to be considered in the optimisation include the highest heat transfer and the lowest stress that can be achieved by the
optimum cooling channel die design. The optimum design was determined by conducting a simulation and was validated by
conducting an experiment. The temperature distribution of the FEA model was at most 5% different from the experimental
results. The optimum cooling channel design of hot press sheet metal forming can produce ultra-high strength steels which tensile
strength and hardness are 51 and 83% greater than those of original boron steels. The heuristic method can also be applied to
optimise the cooling channel die design for the production of ultra-high strength steels in the automotive manufacturing industry.
Keywords Hot press forming
.
Cooling channel design
.
Heuristic optimisation
.
Ultra-high strength steels
.
Finite element
analysis
1 Introduction
The traditional cold stamping method is unsuitable for the
production of ultra-high strength steel (UHSS) due to the
formability of this material. To overcome this technological
barrier, sheet stamping industries are actively developing hot
press forming technologies that can significantly improve the
formability of high strength steel [1]. Apart from ensuring the
high strength and dimensional accuracy of steel sheets, these
technologies can avoid the spring back problem of cold
stamping for high-strength steel and achieve weight reduction
[2–4]. Much effort has been directed towards the development
of lightweight components and structures for automotive ap-
plications. Those lightweight vehicles that utilise UHSS have
chassis components, including A-pillar, B-pillar, bumper, roof
rail, rocker rail and tunnel [5].
The cooling channel inside the tool primarily aims to dissi-
pate heat from the tool and control the tool temperature. In this
modification, fluid is placed inside the tool as a cooling medi-
um. The heat transfer coefficient can be determined by deter-
mining the velocity of fluid inside the cooling channel. Placing
the cooling system with a cooling channel near the tool contour
is currently known as an efficient solution. The cooling channel
must be placed as near as possible to the tool contour to guar-
antee an efficient cooling but must also be placed at an adequate
distance away from the tool contour to avoid any deformation
in the tool during the hot forming process [6]. All generated
solutions are evaluated by using optimum criteria, including
efficient cooling rate and uniform heat transfer.
The design criteria that need to be considered include the
optimum diameter of cooling channels, the pitch and distance
between these channels and the loading surface. These criteria
are determined by applying several optimisation methods,
some examples of which can be found in the literature. For
instance, Hu and Ying [6] and Steinbeiss et al. [7]employed
an evolutionary algorithm, Jiang et al. [8], Kumar et al. [9]and
Liu et al. [10] performed a numerical simulation and Zhong-
* Ahmad Razlan Yusoff
razlan@ump.edu.my
Mohd Fawzi Zamri
fawzizamri@gmail.com
1
Faculty of Manufacturing Engineering, University Malaysia Pahang,
26600 Pekan, Pahang, Malaysia
The International Journal of Advanced Manufacturing Technology
https://doi.org/10.1007/s00170-018-2097-4
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