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C. Rajkumar et al.
commonly used in automobiles, food, petroleum, power, transportation, paper, and
pulp industries. In particular, automotive exhaust systems are one of the major applications of Powder Metallurgy products. Duplex Stainless Steels includes similarly
voluminous austenite and ferrite phases, i.e., 50:50. To maintain the equal phases
of ferrite and austenite alloying elements are added in the correct proportion. DSS
gains the combined advantages of these two phases [1]. Ferritic Stainless Steels are
inferior in toughness and weldability than DSS. Similarly, Austenitic Stainless Steels
have lower pitting resistance and lower corrosion resistance relative to DSS.
DSS may be manufactured by several methods. But, the fabrication of DSS by
powder metallurgy is low cost and near net shape. The first mode of achieving duplex
structure was obtained by pre-alloyed powders [2]. The second mode was to combine
individual elementary powders including chromium, nickel, and molybdenum with
austenitic, ferrite powders in the right proportions to obtain bi-phase microstructure
[3]. Elements such as molybdenum, nickel, and chromium present in DSS make it
strong and responsible for corrosion and mechanical properties. Undesirable phases
such as sigma, secondary austenite has reducing effects on mechanical and corrosion
properties of DSS due to embrittlement [4]. Apart from the sigma phase, non-metallic
inclusions in steels also have a negative impact on corrosion and mechanical properties [5, 6]. Several researchers reported that sigma phase takes place when steels
underwent annealing at less than 1000 °C and it can take away by solution treatment,
controls the mixture of austenite and ferrite [7, 8].
The sigma phase (rich in chromium, molybdenum) has enhanced wear resistance
of DSS with different manganese contents [9]. From literature, it has been observed
that the effects of sintering temperature on the mechanical characteristics of stainless
steel products are higher than that of sintering time [10]. Wear Characteristics of
DSS have been attempted by some researchers [11, 12]. The friction influenced
the mechanical behavior of DSS [13]. The wear properties of aluminum matrix
composites depend upon sliding distance and it is the key factor affecting wear
behavior of the composites [14]. The wear behavior of DSS mainly depends upon
chromium content in DSS [15]. Design of Experiments applies statistical methods
so the effect of the variable can be used to determine the outcome of the required
process or product reported by Sorrentino et al. [16]. The data for wear behavior
of PM DSS using Taguchi’s approach is very limited in the literature. So, the main
goal of this research work is to make DSS using pre-alloyed powders like 310L and
430L and to test wear properties under different loading conditions and analyzed
statistically by Taguchi’s Design of Experiments.
2 Materials and Processes
Two atomized powders namely 310 L and 430 L are mixed for 12 h in pot mill (ASE,
EIE Instruments Pvt. Ltd.,) with chromium, nickel, molybdenum, and manganese.
To consolidate the powders to required shape and size compaction is carried out in
Universal Testing Machine (FIE Model, Hitech India) at 550 MPa. In the hot press
C. Rajkumar et al.
commonly used in automobiles, food, petroleum, power, transportation, paper, and
pulp industries. In particular, automotive exhaust systems are one of the major applications of Powder Metallurgy products. Duplex Stainless Steels includes similarly
voluminous austenite and ferrite phases, i.e., 50:50. To maintain the equal phases
of ferrite and austenite alloying elements are added in the correct proportion. DSS
gains the combined advantages of these two phases [1]. Ferritic Stainless Steels are
inferior in toughness and weldability than DSS. Similarly, Austenitic Stainless Steels
have lower pitting resistance and lower corrosion resistance relative to DSS.
DSS may be manufactured by several methods. But, the fabrication of DSS by
powder metallurgy is low cost and near net shape. The first mode of achieving duplex
structure was obtained by pre-alloyed powders [2]. The second mode was to combine
individual elementary powders including chromium, nickel, and molybdenum with
austenitic, ferrite powders in the right proportions to obtain bi-phase microstructure
[3]. Elements such as molybdenum, nickel, and chromium present in DSS make it
strong and responsible for corrosion and mechanical properties. Undesirable phases
such as sigma, secondary austenite has reducing effects on mechanical and corrosion
properties of DSS due to embrittlement [4]. Apart from the sigma phase, non-metallic
inclusions in steels also have a negative impact on corrosion and mechanical properties [5, 6]. Several researchers reported that sigma phase takes place when steels
underwent annealing at less than 1000 °C and it can take away by solution treatment,
controls the mixture of austenite and ferrite [7, 8].
The sigma phase (rich in chromium, molybdenum) has enhanced wear resistance
of DSS with different manganese contents [9]. From literature, it has been observed
that the effects of sintering temperature on the mechanical characteristics of stainless
steel products are higher than that of sintering time [10]. Wear Characteristics of
DSS have been attempted by some researchers [11, 12]. The friction influenced
the mechanical behavior of DSS [13]. The wear properties of aluminum matrix
composites depend upon sliding distance and it is the key factor affecting wear
behavior of the composites [14]. The wear behavior of DSS mainly depends upon
chromium content in DSS [15]. Design of Experiments applies statistical methods
so the effect of the variable can be used to determine the outcome of the required
process or product reported by Sorrentino et al. [16]. The data for wear behavior
of PM DSS using Taguchi’s approach is very limited in the literature. So, the main
goal of this research work is to make DSS using pre-alloyed powders like 310L and
430L and to test wear properties under different loading conditions and analyzed
statistically by Taguchi’s Design of Experiments.
2 Materials and Processes
Two atomized powders namely 310 L and 430 L are mixed for 12 h in pot mill (ASE,
EIE Instruments Pvt. Ltd.,) with chromium, nickel, molybdenum, and manganese.
To consolidate the powders to required shape and size compaction is carried out in
Universal Testing Machine (FIE Model, Hitech India) at 550 MPa. In the hot press