Improvement of High Temperature Oxidation of Low Carbon Steel Exposed to Ethanol Combustion Product at 700 °C by Hot-dip Aluminizing Coating

Low carbon steel (AISI 1005) was coated by hot-dipping into a molten Al-10% Si bath at 700 °C for 18s. After hotdipping treatment, the coating layers consisted of Al, Si, FeAl3, τ5-Fe2Al8Si, and Fe2Al5. The bare steel and thealuminized steel were isothermally oxidized at 700 °C in ethanol combustion product at atmospheric pressure for 49 h. The aluminized steel shows good performance in high temperature oxidation because the formation of Al2O3 layer on the coating surface. The growth of iron oxide nodules on the surface coating was accelerated by rapid outward diffusion of Fe-ions due to the presence of H2O-vapour generated by ethanol combustion. Thus, the oxidation rate of aluminized steel increased, resulting in a substantial mass-gain as the oxidation time increased. After longer exposure, the τ1-(Al,Si)5Fe3 phase was completely transformed to the FeAl in the outer layer. The FeAl formed near the steel substrate was due to Fe-atoms diffusing into the Fe2Al5 layer when the time and temperature increased

Studi Perilaku Kegagalan Sambungan Las Tipe TConjunctions Pada Baja Karbon Rendah Dengan Pendekatan Experimen Dan Numerik

This research is conducted to investigate failure behavior of welding structure in T-conjunctions type. Welding joint failures were analyzed by both experimental and finite element analysis (2D) approach in terms of stress intensity factor mode I (KI). The stress at the welding zone was strongly influenced by specimen geometries and the ratio of L/h1. The stress intensity factor (SIF) was increased significantly. Whereas, the minimum SIF of specimen #X1 and #Y3 are 58 MPa.√m and 165 MPa.√m, respectively. Failure of welding specimen was more dominated in the zone with the highest stress concentration and also affected by material discontinuity at which the stress was not generated continuously, but localized in any certain area. Specimen without welding did not yield a maximum stress. However, plastic zone formation locally decreases the stress concentration. Discontinuity in the welding specimen does not give rise to plastic stream, thus it will raise the stress concentration at the welding extension region. Discontinuity can be observed by the Von Misses stress pattern at stress welding zone for the welding specimen whereas the specimen without welding was only occurred near the extension zone

Efek Shot Peening Terhadap Korosi Retak Tegang (SCC) Baja Karbon Rendah Dalam Lingkungan Air Laut

The aim of this study is to investigate the effect of shot peening on stress corrosion cracking of a low carbon steel in ocean water environment. The dimension of specimens were prepared in accordance with the ASTM G39. The hardness testing was carried out using microvickers with 0,25 kgf load in the longitudinal direction. The corrosion cracking test was immersed into artificial sea water for about 7 months. The test shows that the pitting corrosion is dominantly nucleated at the metal film interface. The biggest pitting corrosion was occurred under the static loading of 70 for the specimens unpeened. The presence of pitting corrosion promotes stress corrosion cracking. The cracking has a intergranular branched morphology which is typical for the chloride cracking of low carbon stee

Pengaruh Kadar Karbon Dalam Baja Pada Proses Pelapisan Aluminium Celup Panas

Carbon steel is widely used as a component of engineering work in high temperature conditions. During the application decreases of oxidation resistance drastically. A steel coating is very needed to increase an oxidation resistance. One technique is inexpensive and used to be coating for large components are hot dip coating. This experiment aimed to determine the effect of carbon content in steel AISI 1020, AISI 1045 and AISI 1090 against hot dip aluminium coating on hot dip aluminium coating process and to study the influence of immersion time in the tub aluminium molten steel on the growth of intermetallic layer. Immersion times used were 4, 9, and 16 seconds with a temperature of 700 °C. Volume composition used for each solution is 100 ml flux with three variations, namely Y1 flux ( 1.5 g KF, NaF 1.5 g, 8.5 g Borax , and 2.5 g of acetic acid ), Y2 ( 2.0 KF g, 2.0 g NaF, 9.5 g Borax, and 3.0 acetic acid ) and Y3 ( 2.5 g of KF, 2.5 g NaF, 10 g Borax, 3.5 g acetic acid ). Then do the impact test , SEM , OM and XRD. For the most thick aluminium layer was AISI 1020 steel with immersion time of 4 seconds is 0.118 mm and Fe - Al intermetallic layer ( FeAl3+Fe2Al5 ) is the thickest on AISI 1045 steel with immersion time of 9 seconds. Energy values were greatest impact on AISI 1020 steel is 187.2 J, means less carbon content of the energy generated greater impact

Pengaruh Komposisi Deposit Nacl/na 2 So Terhadap Korosi Temperatur Tinggi Baja Aisi 4130 Yang Dilapisi Aluminium 4

Steel AISI 4130 is a combination steelof 1,0 Cr-0,25 Mo-Fe that mostly used for the component heat axchanger and pipe steam boiler. However in a high temperature and contain of corrosive gas like klor and sulfur,the endurance of the corrosion of steel AISI 4130 declines. It is important to do a research for increasing the endurance of the corrosion of the steel AISI 4130 with heated Al layered in the surface of steel AISI 4130 Al layered and oxidized in temperature 750°C during periods 1-49 jam. The calibration of the corrosion is done with the variation of deposit NaCl/Na The finding of the research shows that the existence of deposit NaCl/Na2 SO in the steel Al layered brings a large influence oxidation kinetics steel, it is proven through the largest value of parabolic constants of the steel AISI 4130 with Al layered with the comparison of deposit NaCl/Na4(gr):30/70 is 6,89 × 10-9 g2 cm–4 s–1. Whereas the value of parabolic constants with the comparison of deposit (gr): 100/0 is 2,71 × 10 -9 g2 cm–4 s–1, 50/50 is 6,15 × 10 -9 g2 cm–4 s–12 SO24SO4 , 70/30 is 2,97 × 10 g2 cm –4 s–1 and 0/100 is around 2,60 × 10 -9 g 2 cm –4s–1. The destruction of the protective layer Al in the aluminide layer is caused by the existence of klor dan sulfur from the deposit NaCl/Na2SO4 thattriggersthe growthofiron-rich ovide (FeO)

Karakterisasi Sifat Mekanik Dan Struktur Mikro Baja Carbon Rendah Untuk Cane Cutter Blade Pada PT Gunung Madu Plantation

Cane cutter blade (blade chopper cane), which is a tool used for chopping cane. This tool acts as a cane crusher, made of low steel carbon. Constraints that occur on Cane Cutter Blade is a high wear rate, thus disrupting the productivity of the industry. The company handles this problem by providing a coating on a cane cutter blade, only in this way is still considered very less effective at. low steel carbon relatively low carbon steel.Characterization of the mechanical properties and the microstructure of low steel carbon with hardness testing and tensile testing, while the micro picture of choice to see the results of the condition of the microstructure after a heat treatment with water as cooling media

Stress Corrosion Cracking Behavior of Stainless Steel 304 in the Sulfuric Acid Environment Due to Prestrain

Theaim of  research is to investigate the effect of prestrain  on the stress corossion cracking behavior of AISI 304 stainless steel in the sulfuric acid of 10% concentration  under the static cantilever loading according to ASTM E-1681 standart. The specimen of 304 Stainless steel was strain up over the yield strength until reaching the uniform strain of 5% and 10% using servopulser UTM 9506 under the  displacement control of 0,3 mm/sec. The results of test  show that the prestrain of 5%  specimen is faster  failure than both  of  the prestrain of 10% and unprestrain specimen. It was caused by both of the decrease of ductility and  the short   incubation period. The change of deflection could be only recorded under  the loading 20% of yield strength. Intergranular crack was the prestrain of 10% specimen under the static loading of 616 MPa. Whereas,  for the prestrain of 10% specimen transgranular crack  was found under the static loading of 554,4 MPa. The prestrain of 5% specimen was mixed crack  under the static loading of 369.6 MPa. Higher dislocation density on the layer surface due to plastic deformation with increasing the percentage of pre-strain, so more difficult hydrogen diffused into the crack tip. Consequently, The incubation period can be prolonged

Pengaruh Rasio Regangan terhadap Perilaku Llow Cycle Fatigue (LCF) Paduan Al 7075-T7

The aluminium 7075 alloy is widely used in the aircraft industry for components on the front spar, stabilizer, frames that requires a high strength and low density ratio.The aerospace and automotive industries need to design for lightweight materials, where aluminum alloys are often used as the main component.Aluminum alloyshave good corrosion resistance properties. This material is used in a wide field not only for household appliances but also for industrial purposes, for example air-craft, car, marine and other constructions.The phenomenon of ductility decreasing due to pre-fatigue deformation, is the most significant for the combination of long pre-fatigue time, high humidity, and low strain rate.The process of making specimen shapes and dimensions were prepared according to ASTM E8 standard for the tensile specimens and ASTM E606 standardfor LCF test, respectively. Characterization of changes in material structures and the types of failure that occuredwerecarried out using OM, SEM and EDX