3 results listed
In this study, low alloy Cr-W steels containing 3%
and 5% Cr and 3% W as main alloying element were produced
via casting in ceramic mold and then hot rolled. Steels were
produced both without Ta and with 0.1% by weight Ta. The
purpose of this study is to investigate the effects of addition of Ta
as alloying element to the microstructure and hardness of low
alloy Cr-W steels. Before microstructure characterization and
hardness test all samples were heat treated. Heat treatments
were performed as (annealing, air quenching) and (annealing, air
quenching and tempering). Annealing were performed at 1100 ℃
for 1 hour and tempering were performed at 710 ℃ for 2 hours.
Microstructures were analyzed by optical microscope and the
Brinell hardness test was used to determine the hardness of
steels. 3 Cr steel has a microstructure of ferrite and bainite. 3 Cr
steels containing 0.1% Ta has a microstructure of ferrite and
bainite, too. But Ta-containing 3 Cr steel has less ferrite than Tafree 3 Cr steel. 5 Cr steel has a microstructure of bainite and
martensite. 5 Cr steels containing 0.1% Ta has a microstructure
of bainite and martensite, too. But Ta-containing 5 Cr steel has
less bainite than Ta-free 5 Cr steel. 5 Cr steels which annealed
and air quenched have highest hardness and 5 Cr steel which
annealed, air quenched and tempered has lowest hardness.
International Iron & Steel Symposium
UDCS
Gökhan Arıcı
Mesut Uyaner
Mustafa ACARER
In this study, Fe-5Cr-3W steels containing without Co
and 1.5 wt% Co were produced via casting and following that
they were hot rolled. The effect of Co addition on microstructure
and hardness of steels after heat treatment ((annealing, air
cooling) and (annealing, air cooling and tempering)) was
investigated. Co-free and Co-contained steels have bainitic and
martensitic microstructure. However, martensite volume
fraction of Co-free steel is higher than Co-containing steel.
Hardness of air quenched samples was decreased after
tempering. Co increased hardness slightly both air quenched and
tempered samples.
International Iron & Steel Symposium
UDCS
Gökhan Arıcı
Mustafa ACARER
Mesut Uyaner
AISI 430 ferritic stainless steel have almost same mechanical and microstructural properties and corrosion
resistance as austenitic stainless steels. In addition, these steels are as cheap as austenitic stainless steel. On
the other hand, they lose their strength and toughness at high temperatures. Nowadays, demand to those
steels has been increasing due to their convenient properties. AISI 430 ferritic steels are widely used in
construction sector, automotive industry and food industry.
The aim of usage of strain aging is driving a strengthening mechanism to increase mechanical properties of
AISI 430 stainless steels. This mechanism is based on the principle of increasing dislocations are locked by
themselves or carbon and nitrogen atoms after cold deformation. After strain aging, tensile strength and
yield strength increase but ductility decreases. Strength and elongation of samples change by altering heat
treatment temperature and amount of deformation. The influence of quantity of pre-strain and aging
temperature to yield strength, tensile strength and tensile elongation, on AISI 430 stainless steels samples
was studied. Identical samples first are pre-strained in tension to a uniform elongation of 5%, 10% and 15%
and then aged at 150 °C, 200 °C and 250 °C for 15 minutes, separately. After pre-strained aging process the
mechanical properties of final products are compared with untreated AISI 430 steel. It was observed that
yield and tensile strength of samples increased with increasing quantity of pre-strain for the same aging
temperatures. Also, all heat-treated samples have higher strength than untreated samples. For %5 prestrained conditions, yield and tensile strength slightly decreased and after then increased by increasing
temperature from 150 °C to 200 °C and from 200 °C to 250 °C, respectively. Breaking strength increased
by increasing aging temperature for %5 pre-strained. For %10 pre-strained condition, specimens have
maximum tensile, yield and breaking strength values for aged temperature of 200 °C. For %15 pre-strained
conditions, yield, tensile and breaking strength values are highest at 200 °C. Breaking elongation of samples
decreased by increasing pre-strain rates for all temperatures. Breaking elongation of samples is minimum
for %10 pre-strain rate at constant aging temperatures.
International Iron & Steel Symposium
UDCS
Gökhan Arıcı
Mustafa ACARER
Mesut Uyaner