Corrosion Rate Of Carbon Steel Research Articles

Evaluation of the Effect of Static and Flowing Conditions on the Corrosion Behavior of the Hull of Marine Ships

Marine ship hulls' corrosion resistance behavior under static and flowing conditions was investigated. The metal of the hull panels of marine ships was chemically and mechanically examined and analyzed, revealing that carbon steel type DIN 1.0501 C35 is employed in constructing the hull of ships in the port of Basrah in Iraq. A corrosion resistance test for this metal was carried out in laboratory-prepared seawater under static and flowing conditions at a flow rate of 1500 liter/hour and various immersion times (12, 24, 48, 120, 168, 336) hours. The temperature was kept constant at 30°C, and a fixed salt concentration of (3.5% sodium chloride). The corrosion rate of C35 carbon steel was calculated using the weight loss method is an effective method for calculating the corrosion rate of carbon steel. The samples were examined using a scanning electron microscope (SEM) for corrosion analysis. Conclusions from this research indicate that an increase in the flow rate resulted in an elevation of the corrosion rate, doubling the corrosion rate compared to samples under static conditions. The corrosion rate exhibited a significant increase during the first 24 hours, followed by a gradual decrease with increasing immersion time. The corrosion rate increased by 682.9%. The speed of corrosion was fast initially, but the weight loss slowed after 24 hours of immersion. A scanning electron microscope (SEM) examination revealed that the flow environment was aggressive for carbon steel. It was much more severe, and the pits and grooves were more significant than the static condition.

A novel corrosion inhibitor of bis-benzimidazole derivative for mild steel: Synthesis, properties and mechanism investigation

The application of corrosion inhibitor is still one of the effective ways to protect metals under high temperature and high pressure environment. In this paper, we have introduced a synthetic method for a novel bis-benzimidazole derivative, i.e., N, N-bis (-2-heptadecyl-benzimidazole) -1-hexylammonium chloride (HBH), and its solubility was improved by adding a specific surfactant (AEO-5) to form a highly efficient corrosion inhibitor system (HBH-A), and its corrosion inhibition was studied by weight loss, electrochemical measurements, SEM, EDS and XRD. The results showed that HBH-A inhibited the corrosion of N80 carbon steel in the corrosive medium. As the concentration of HBH-A increases, the corrosion inhibition rate exhibits a pattern of rapid initial growth followed by a slower increase. Electrochemical measurements demonstrate that HBH-A behaved as an effective mixed-type corrosion inhibitor, exhibiting a significant enhancement in the corrosion inhibition rate (η) with increasing concentrations of HBH-A. At a HBH-A concentration of 100 mg⋅L-1, the inhibition rate can outstrip 98 %. Corrosion surface analysis further confirm that the HBH molecules are indeed adsorbed to form an adsorption film, and the surface exposure of N80 carbon steel was significantly decreased with the action of HBH-A, thus reducing the corrosion rate of N80 carbon steel.

Bioinduced corrosion of carbon and alloyed steel by thermophilic microorganisms in the presence of uranyl ions under anaerobic conditions

Intensification of corrosion in short-term experiments on carbon (СS) and stainless (SS) steel as materials for underground radioactive waste disposal by thermophilic microbial communities isolated from neutral (Tuva region) and alkaline thermal radionuclide-enriched environments (Tau Tona mine) in the presence of uranium under anaerobic conditions was studied. The corrosion rate of carbon and stainless steel in the presence of the Tau Tona culture increased up to 14 and 3.7 times, respectively. The increase correlated with the predominance of metal-reducing bacteria in the culture. The culture from Tuva, dominated by fermentative bacteria, increased the corrosion rate 6 to 4 times, depending on the type of steel and organic substrate. The main mechanism of microbial corrosion of both types of steel was the dissolution of passivating corrosion products, mainly magnetite, due to their reduction by iron-reducing bacteria or chelation by metabolic products of fermenting bacteria. Surface corrosion was observed on carbon steel and pitting on stainless steel. In the presence of uranyl ions, the corrosion rate of both types of steel increased up to 19 `. Uranyl ions can be reduced to UO2 by microorganisms and will not further affect steel oxidation, furthermore, accumulation of reduced forms of uranium in corrosion products may passivate steel corrosion. It was found that in the presence of organic substances in the environment it can intensify chemical corrosion processes of both types of steel due to the complexation of steel corrosion products, preventing the formation of a passivating corrosion layer. Thus, in the presence of acetate, the corrosion rate of black and stainless steel was 12–36 % higher, in the presence of trehalose it increased the corrosion rate by 1–24 %.

Mineralogical and geochemical composition of a cementitious grout and its evolution during interaction with water

In the present study, the chemical composition, mineralogy, and mechanisms of alteration of a cementitious grout based on a CEM III/C with addition of smectite, hydrotalcite, and silica fume, are studied using a combination of chemical and physical methods. This material was designed in the context of geological repository of radioactive wastes, with a twofold aim: first, to fill the technical voids left by drilling operations at the interface between the geological formation and the disposal galleries. Second, to neutralize a potential acidic transient due to pyrite oxidation, and to create an environment that favors low corrosion rates of carbon steels. The grout is mainly composed of calcium silicate hydrates having a Ca/Si ratio of ~0.8, incorporating Al in the bridging site of the Si chains (C-A-S-H), and accounting for 29–36 wt.% of the sample. It also contains silica fume (38–48 wt.%), smectite with interlayer Na (11–17 wt.%), hydrotalcite with interlayer CO32− (3–4 wt.%), and lower amounts of portlandite, calcite, and possibly gibbsite and gypsum. Upon alteration by water in a flow-through reactor, the main modifications affecting the sample are calcite and gypsum dissolution, hence releasing aqueous Ca2+ that is adsorbed in smectite interlayer by replacing Na+, and stoichiometric C-A-S-H dissolution. The evolution of solution chemistry and of the solid phase composition are reproduced successfully using a thermokinetic model.

Monitoring atmospheric corrosion under multi-droplet conditions by electrical resistance sensor measurement

This paper presents a novel approach to investigate atmospheric corrosion kinetics of carbon steel under multi-droplet conditions. A homemade climate chamber has been developed to accurately control and monitor environmental conditions, including temperature (T) and relative humidity (RH), during exposure. Carbon steel corrosion kinetics are monitored with a custom-designed Electrical Resistance (ER) sensor pair. Savitzky-Golay (S-G) based filtering technique has been used for the corrosion signal processing. In parallel, top-view droplet temporal evolution has been recorded by microscopic imaging and analyzed for both droplet size distribution and the solid-liquid contact angle. The droplet size distribution can typically be described with a power-law form curve. The curve shows a decrease in height and a concurrent expansion in width with progressive drying. The introduction of NaCl into the electrolyte and surface roughness variations have also been identified to substantially influence the carbon steel corrosion rate. A strong correlation between the corrosion rate derived from the ER monitoring method and the RH can be observed. This correlation is further analyzed to incorporate the impact of droplet-based electrolyte conditions. This study offers valuable insights into the development of mechanistic and kinetic prediction models for atmospheric corrosion.

Karakterisasi Tebal Lapisan Dan Ketahanan Korosi Mild Steel SS400 JIS G3101 Dengan Metode Elektroplating Ni-Cr

Mild steel is steel with a concentration of carbon element below 0.3%. In its use as an oil storage tank material on fuel transport trucks, there is a problem, namely its resistance to corrosion in fuel. Sulfur compounds in fuel have a role in the formation of corrosion. Currently, the Ni-Cr electroplating coating method is very widely used as an effort to control the corrosion rate of carbon steel. The use of Ni-Cr as an anode is relied upon as a substance resistant to corrosion. Therefore, the purpose of this study was to identify how layer thickness affects corrosion levels in SS400 mild steel based on current variations and duration of the electroplating process. In this study using mild steel SS400 JIS G3101 with electroplating method (electroplating) varying the electric current 1A, 2A and 3A, as well as electroplating time of 10 minutes, 20 minutes and 30 minutes. The test parameters of the electroplating results are the actual layer thickness test, theoretical thickness test and corrosion rate test. Data processing was analyzed using two-way variance analysis. The thickness of the layer increases with increasing electric current and the length of time of Ni-Cr electroplating. The highest thickness value of 102.34 μm using a digital microscope while for theoretical testing of 98.33 μm, both were obtained at a current variation of 3A and an electroplating time of 30 minutes. The trend of corrosion rate value will decrease with the increase in electric current and the length of electroplating time with the lowest value of 0.003359 mmpy at a variation of electric current 3A and electroplating time of 30 minutes. For optimal values with the lowest corrosion rate on mild steel SS400 JIS G3101 as an oil storage tank material on fuel transport trucks, it is obtained by using a current of 3A and an electroplating time of 30 minutes Ni-Cr.

The Effect of Flow Velocity on Corrosion and Corrosion Mitigation of Carbon Steel in Wide Range of Sulfuric Acid Concentration

The impact of flow velocity (0-900 rpm) on the corrosion rate of carbon steel in a wide range of sulfuric acid concentrations (0-90% in H2O) at 30 °C and 1 h was studied and discussed. In addition, the efficiency of corrosion inhibitor (dimethyl disulfide, DMD) was evaluated in hardest corrosion conditions for the range of velocity investigated. The results revealed that increasing the flow velocity of H2SO4 solution, increases the corrosion rate depending on the acid concentration. When the flow velocity is increased of H2SO4 solution, the corrosion potential was shifted to more negative. The DMD inhibitors showed significant inhibition efficiency at high velocities, where the highest percentage of inhibitor efficiency reached 98% at 900 rpm.

Corrosion protection characteristics of doped magnetite layers on carbon steel surfaces in aqueous CO2 environments

Magnetite (Fe3O4) corrosion product surface layers can limit uniform corrosion rates of carbon steel in aqueous carbon dioxide (CO2)-saturated environments. However, as Fe3O4 is a semiconductor, localised corrosion can proceed due to galvanic interaction between the Fe3O4 layers and bare steel. In this study, metal dopants were integrated into Fe3O4 layers to mitigate the effects of localised corrosion, whilst maintaining its protective barrier properties. Model Fe3O4 and metal-doped Fe3O4 layers were electrodeposited on carbon steel and immersed in a pH 5, 1 wt% sodium chloride (NaCl), CO2-saturated, 50 °C solution. Under the conditions studied, the incorporation of magnesium into the Fe3O4 layer resulted in reduced localised corrosion when the 3D surface profiles of the underlying carbon steel were measured using white light interferometry.

Research on Metal Corrosion Behaviour of Indirect Air-cooled Circulating Water System

Abstract The indirect air cooling system of an air-cooled power plant consists of a surface condenser and an aluminum radiator. The radiator is usually made of 1050A pure aluminum, and the circulating water pipe connecting the radiator is made of Q235B carbon steel. This article simulates and controls typical water quality parameters such as dissolved oxygen and pH value in indirect air cooling systems using a self-designed simulation device, and studies the influence of various water quality parameters on material corrosion behavior in intercooled circulating water systems when aluminum and carbon steel coexist. The results indicate that factors such as dissolved oxygen, conductivity, pH value, temperature, and redox potential can all affect the corrosion rate of carbon steel and aluminum materials; The increase in temperature and dissolved oxygen leads to an increase in corrosion rate; The main way carbon steel corrodes the system is by consuming dissolved oxygen; The corrosion behaviour in the water circuit will lead to an overall decrease in pH value. In the presence of multiple metals, the influence of iron ions in the solution significantly increases the corrosion rate of aluminum.

The effect of different heavy metals pollutants in refinery effluent on corrosion rate of carbon steel

The presence of heavy metal pollutants in refinery effluent significantly impacts the corrosion rate of carbon steel. The focus of this research is to analyze the impact of various inorganic pollutants, including copper, vanadium, nickel, and chromium ions, on the corrosion of carbon steel across different solutions. After conducting a thorough examination of various operating conditions, including pollutant concentration (ranging from 300-3000 ppm), temperature (30-60? C), and flow velocity (0-800 rpm). Our research shows that copper ions have the highest corrosion rate, with vanadium ions being a close second. Conversely, nickel and chromium had the most negligible impact on corrosion rate and, in some instances, even exhibited corrosion inhibition effects. It was also observed that an increase in flow velocity and temperature significantly amplified the corrosion rate of the metal ions investigated.

Effect of seawater flow velocity in South Malang on the corrosion rate of low carbon steel with a corrosion coupon rack

Corrosion is a phenomenon of damage to metal that can be influenced by several factors, including environmental factors, namely pH, humidity, temperature, and impurity factors. Corrosion that occurs due to the flow of a fluid is known as erosion corrosion. One type of metal that is susceptible to corrosion is carbon steel. Carbon steel material is very commonly used in the industrial world. An application of carbon steel is in piping systems that transport fluids; thus, fluid flow velocity affects the corrosion resistance of carbon steel. This research aimed to determine the effect of seawater flow on the corrosion rate of low carbon steel (ST 37) with variations in seawater velocity. This research is a type of laboratory-scale experimental research using coupon rack corrosion test equipment. The variations in seawater velocity used are 0 L/min, 15 L/min, 20 L/min, and 25 L/min. Observations of each experiment were carried out every 6 and 12 hours. The corrosion rate was analyzed using the weight loss method, namely by calculating the initial and final weight of the specimen before and after the experiment. The results show that increasing seawater flow velocity also increases the corrosion rate on steel specimens, with the lowest corrosion rate at 10.262 mpy on specimens with a variation of 0 L/min, while the highest corrosion rate is 48.743 mpy on specimens with a variation of 25 L/min. It can be concluded that the velocity of the fluid flow and the type of particles contained in the flow affect the rate of erosion-corrosion. The higher the fluid flow velocity and the more abrasive the particles contained in the flow, the faster the rate of erosion-corrosion.

Effect of tetrakis(hydroxymethyl)phosphonium sulfate (THPS) on the microbial community and corrosion of carbon steel in a simulated crude-oil storage tank environment

The biocorrosion process has been a problem for the oil and gas industry, involving deterioration of facilities, loss of oil quality, metal loss, and oil leaks. In oil storage tanks, the presence of a metallic surface along with crude oil and water poses a biocorrosion risk. Biocides are used to control the biocorrosion of different metallic infrastructures, tetrakis(hydroxymethyl)phosphonium sulfate (THPS) is commonly used due to its low environmental impact and its effectiveness in preventing sulfate-reducing bacteria (SRB) growth. The treatment effect with one THPS application on microbial community and corrosion rates was evaluated in a batch fractionated assay containing water from a crude oil storage tank, carbon steel coupons and crude oil. The effects of the treatment were monitored for 60 days. The number of planktonic bacteria and archaea estimated by qPCR decreased at the beginning of the treatment with THPS, however, 60 days after the application their number was higher, as were the sulfate-reducing microorganisms (SRM) and methanogens (MA). The diversity analysis of the 16S rRNA gene showed that the relative abundance of the genus Desulfovibrio and Methanocalculus was higher on day 8 in the presence of THPS, but by day 60 there were no differences. The biocide did not inhibit bacterial and archaeal biofilm attached to the SAE 1010 carbon steel coupons and produced a decrease in corrosion rates by blocking the surface. The proximity of the corrosion potential to the pitting potential indicated a high susceptibility to localized corrosion. The results suggested that the changes in the microbial community by THPS treatment were related to the corrosion rates of carbon steel, rather than the number of microorganisms attached to the coupon.

Inhibition of Acid Descaling and Pickling Effects on API 5CT Carbon Steel Using Schiff Base Ligand (C24H21N5O2) in 1 M H2SO4 Solution

The objective of this paper was to investigate the inhibition of acid descaling and pickling effects on API 5CT carbon steel using Schiff base ligand (C24H21N5O2) in 1 M H2SO4 solution using Potentiodynamic Polarization (PDP), Electrochemical Impedance Spectroscopy (EIS) and Weight Loss (WL) techniques. FTIR spectroscopy shows that there was a strong adsorption of SFBL on the carbon steel surface due to formation of a complex surface film. Corrosion rate of carbon steel decreased exceedingly from 0.0155 to 0.0002 while inhibition efficiency of SFBL rose from 78.8 % to 98.9 % between 20 ppm and 100 ppm respectively. PDP measurements revealed a mixed type inhibitor. EIS measurement reveals that the increasing charge transfer resistance was directly proportional to the increase inhibitor concentration and the double layer capacitance dropped from 1.98 to 0.61 indicating a stronger inhibition.

Effect of Adsorption and Interactions of New Triazole-Thione-Schiff Bases on the Corrosion Rate of Carbon Steel in 1 M HCl Solution: Theoretical and Experimental Evaluation.

Due to the unique properties of steel, including its hardness, durability, and superconductivity, which make it an essential material in many industries, it lacks corrosion resistance. Herewith, two novel triazole-thione Schiff bases, namely, (E)-5-methyl-4-((thiophen-2-ylmethylene)amino)-2,4-dihydro-3H-1,2,4-triazole-3-thione (TMAT) and (E)-4-(((5-(dimethylamino)thiophen-2-yl)methylene)amino)-5-methyl-2,4-dihydro-3H-1,2,4-triazole-3-thione (DMTMAT), were synthesized and characterized. The corrosion inhibition (CI) ability of these two molecules on carbon steel in an aqueous solution of 1 M HCl as well as their interaction with its surface was studied using a number of different techniques. The results confirmed that the CI capability of these organic molecules depends on their strong adsorption on the metal surface and the formation of a protective anticorrosion film. Weight loss tests revealed that the inhibition efficiencies of TMAT and DMTMAT were 91.1 and 94.0%, respectively, at 1 × 10-3 M concentrations. The results of electrochemical impedance spectroscopy (EIS) indicated that there was a direct relationship between the inhibitor concentration and the transfer resistance. Potentiodynamic polarization (PDP) experiments have proven to be mixed-type inhibitors of C-steel in aqueous hydrochloric acid solution and follow the Langmuir adsorption isotherm model. Several thermodynamic and kinetic parameters were calculated. The negative values of the adsorption-free energy are -36.7 and -38.5 kJ/mol for TMAT and DMTMAT, respectively, confirming the spontaneity of the adsorption process. The MD simulation study's findings show that the inhibitor molecules are nearly parallel to the metal surface. The interaction energy calculated by the MD simulation and the inhibitory trend are the same. The practical implementation is consistent with what the computer models predicted.

MICROSTRUCTURE AND EROSION CORROSION PROPERTY OF CRNI ALLOYED COATING ON CARBON STEEL

In this study, CrNi alloyed coating was deposited on Q235 low carbon steel by arc-added glow plasma depositing technique in order to increase the corrosion resistance property. It was found that the CrNi alloyed coating was composed of face-centered cubic Cr0.7Ni2.9Fe0.36 phase. The EDS results indicated that 7.3 [Formula: see text] m coatings were prepared which was bonded metallurgically with the substrate. The salt spray corrosion test result showed that the corrosion product film of coating was dense while the corrosion film of carbon steel was multilayered in morphology. The corrosion product film of CrNi coating reduced the corrosion rate. However, the corrosion product of Q235 with loose multi-layer structure increased corrosion process. The erosion corrosion properties of carbon steel and coating were tested in NaCl solution with different flowing speed through electrochemical test methods. The erosion corrosion results showed that the corrosion rate of carbon steel was increased in flowing NaCl solution. The corrosion product of CrNi coating could protect inner material in NaCl solution at flowing speed of 2 m⋅s[Formula: see text] to 6 m⋅s[Formula: see text].

Ekstrak Daun Matoa (Pometia pinnata) sebagai Inhibitor Korosi Baja Karbon SS-304

Research has been carried out on inhibitors from matoa leaf extract to inhibit the corrosion rate of SS-304 carbon steel. The Matao leaf extract used as an inhibitor was immersed in a 1 M H2SO4 corrosive medium. To determine the effect of inhibitor concentration and immersion temperature on steel corrosion, various inhibitor concentrations were varied, namely 0%, 1%, 2%, and 3% bt, and temperature variations, namely samples also in XRD and SEM characterization. 35°C and 40°C. The corrosion rate test was carried out using the weight loss method. The increase in the corrosion rate is in line with the increase in sample weight loss. The most efficient inhibitor of matoa leaf extract was obtained at a concentration of 3% with an immersion temperature of 35°C, namely 0.09 mmpy. The XRD results showed that the maximum peaks produced FeC and FeNi crystals, followed by FeO crystals. SEM characterization also showed that samples without inhibitors were more corroded, and samples using 3% inhibitor concentrations were slightly corroded.

Effect of turbulent flow on the oxide properties of carbon steel in alkaline water

The purpose of this study is to investigate the changes in the morphology, chemical state, defect density, and impedance of oxides formed on SA 106 Gr.B carbon steel by turbulent water flow at the micro and atomic levels. A compact magnetite layer composed of multi-faceted particles is formed in stagnant water, while a porous magnetite layer composed of particles without a certain shape is formed in turbulent water. Ferrous ions are preferentially dissolved from the oxide in turbulent water, which increases the vacancies in the oxide lattice. An increase in the concentration of point defects is shown to be comparable to an increase in the corrosion rate of carbon steel. The flow-accelerated corrosion behavior is also well correlated with the electrochemical impedance parameters including the charge transfer resistance and capacitance. Our study provides a further understanding of carbon steel corrosion under turbulent water flow conditions.

Synergistic inhibitive effect of a hybrid zinc oxide-benzalkonium chloride composite on the corrosion of carbon steel in a sulfuric acidic solution

Abstract Zinc oxide and quaternary ammonium-type surfactants have been separately recognized for their anti-corrosive efficiencies. Their composite, not investigated so far, could provide a synergetic anti-corrosion effect. In this respect, the aim of this study is to synthesize a composite material consisting of zinc oxide and benzalkonium chloride (ZnO-BAC) in varying mass ratios (3:1, 1:1, and 1:3). The inhibitory properties of the ZnO-BAC composite against carbon steel corrosion in a 0.5 M sulfuric acid solution were assessed under ambient conditions. First, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy were used to examine the chemical structure of the prepared composite. Then, the corrosion inhibitive performance of the devised inhibitors was screened using electrochemical, hydrogen collection, and weight loss measurements. Further, the surface morphology was examined using a scanning electron microscope, both before and after immersion in the corrosion medium. The electrochemical measurements indicate that the prepared inhibitor exhibits a predominant cathodic inhibition behavior and the maximum inhibition efficiency, approximately 91.9%, was achieved for one-to-one mass ratio. Similar results were obtained from weight loss and hydrogen evolution measurements, which showed that the ZnO-BAC composite reduced the corrosion rate of carbon steel by 69.9% and 64.9%, respectively. Finally, molecular dynamics and an adsorption equilibrium model were used to elucidate the mechanism of corrosion inhibition by the ZnO-BAC composite, which exhibits a high adsorption energy on the iron surface.

Monitoring Atmospheric Corrosion of Carbon Steel Under Controlled Electrolyte Droplet Distributions

Field exposure testing and accelerated corrosion testing are two common approaches applied in the industry to assess the atmospheric corrosion rate of a specific material, both relying on visual inspection and weight change of the specimen. Field exposure testing occurs under natural atmospheric conditions but requires exposure times spanning decades, whereas accelerated corrosion testing shortens the exposure time to weeks; however, the connection between the natural environment and accelerated corrosion chamber conditions remains unresolved. Efforts have been made to correlate accelerated corrosion results with those obtained in field exposure based on weight loss, both qualitatively and quantitatively, primarily empirically and limited to small datasets.This work examines the link between modified field exposure testing and the environment from the electrolyte perspective, under controlled laboratory conditions. In-situ monitoring and analysis of corrosion rate, electrolyte condition, and environment are demonstrated to be feasible, and the effect of NaCl concentration and droplet distribution on the atmospheric corrosion rate of carbon steel has been addressed.This work proposes a setup wherein multiple droplet-based conditions are created, and corrosion kinetics are actively monitored using the electrical resistance method. The sample surface is simultaneously monitored with an optical microscope, through which both droplet distribution evolution and corrosion product formation can be visualized.

The Performance of Papaya Leaf Extract on The Corrosion Rate of Carbon Steel in 0.5 M HCl Solution

The performance of papaya leaf extract as a corrosion inhibitor for carbon steel metal in 0,5 M HCl solution was investigated using immersion methods. The measurements were conducted in different concentrations of papaya leaf extract and immersion time. It also investigated the effect of temperature on the corrosion rate of carbon steel without and with the use of papaya leaf extract. It would enhance the corrosion inhibitor regarding these materials since the study is still rarely elaborated. The experiments were conducted using ASTM G-31-72 standard practice for laboratory immersion corrosion testing. The carbon steel corrosion rate and inhibition efficiency were examined. Results show that the concentration of papaya leaf extracts influences the corrosion rate of carbon steel. Higher papaya leaf extract concentration reduces the carbon steel corrosion rate. The increasing immersion time increases the corrosion rate. Moreover, increasing temperatures increase the corrosion rate. The inhibition efficiency increases with the increase of papaya leaf extract concentration. The highest inhibition efficiency is 73.10% which reached a concentration of 5% and immersion times of 5 days.