St3 Steel Research Articles

Tribological behavior of cobalt/graphene composite coatings

Pure cobalt and cobalt/graphene composite coatings were fabricated on St37 steel substrates by using the electrodeposition method. The morphology and microhardness of the coatings were investigated. The tribological behavior of the specimens was evaluated under the normal loads of 5, 10, and 15 N and through the sliding distances of 300, 600, and 900 m at the ambient temperature. SEM images revealed that the graphene particles had been appropriately distributed within the cobalt matrix. Both the cobalt and cobalt/graphene composite coatings had a nodular-pyramidal morphology. However, the morphology of composite coating was finer than that of the pure cobalt film. According to the wear results, both the cobalt and composite coatings exhibited a much better wear behavior compared to the steel substrate. The co-deposition of graphene particles decreased the volume loss and friction coefficient of pure cobalt film. The volume loss increased by the increment of the applied load and sliding distance. However, increasing the normal load decreased the average coefficient of friction in all the samples. The main wear mechanism of all the samples was abrasion, except for the substrate at the high normal loads.

Investigation of pre-sprayed powders for electric contact welding

There are a number of difficulties in the electrical contact welding of powder materials: shedding of powder from the surface of a cylindrical part, impossibility of hardening the layer during welding due to flushing of the powders with coolant and unstable flow of powder into the welding zone. One solution is pre-spraying the powder in some way. (Research purpose). The research purpose is investigating the possibility of electric contact welding of metal powders preliminarily sprayed by a gas-flame method, namely, adhesion strength and losses during preliminary gas-flame spraying of powders. (Materials and methods) Powders of grades PG-NA-01, PrKhIIG4SR, PRZh3.200.28 were sprayed onto flat samples of St3 steel, polished to a roughness of Ra 1.25. The strength of powder adhesion to the base was studied by the cut method. (Results and discussion) The percentage loss of the powder as a whole is 3-23 percent for all the distances studied. The greatest powder losses appear at a distance of more than 180 millimeter from the tip of the burner for powders of grades PG-NA-01 and PrKhIIG4SR. The smallest powder losses were observed for PrZh3.200.28 powder, which totaled 3-7 percent. The maximum adhesion strength of the sprayed powders to the surface was 22.1 megapascals' when spraying the PG-NA-01 powder. The adhesion strength of powders of the grades PrKhIIG4SR and PrZh3.200.28 is small and amounts to 0.2-3 megapascals'. (Conclusions) The use of preliminary flame spraying of powders for their further electric contact welding is possible using PG-NA-01 grade powder, while the best adhesion to the base (that is more than 20 megapascals') is achieved with a spraying distance of 120-140 millimeter. The smallest powder losses during flame spraying are achieved at a spraying distance of 100-160 centimeters', at which the powder loss for the studied grades was 4-12 percent.

Evaluation of the protective efficiency of a volatile corrosion inhibitor of atmospheric corrosion of metals in the presence of aggressive micro impurities of air by impedance spectroscopy method

The protective efficiency of the volatile IFHAN-114 corrosion inhibitor (VCI) was determined by impedance spectroscopy under atmospheric corrosion of St3 steel and copper in livestock buildings containing trace amounts of carbon dioxide, ammonia and hydrogen sulfide in the regulatory allowable concentrations. A 0.1 M NaCl solution was used as the background electrolyte. The effect of the combined presence of NH3 and CO2 corrosion stimulants of metals in the air was modeled by introducing (NH4)2CO3 in concentrations of 10 and 100 mg/L into the background solution. To simulate the combined presence of NH3 and H2S in air, equivalent amounts of Na2S and NH4Cl were introduced into the background electrolyte solution to obtain (NH4)2S (10 and 100 mg/L) at specified concentrations. This resulted in the hydrolysis of NH4+ and S2- ions to form NH4OH and H2S, which are stable in the surface phase film. According to impedance spectroscopy, (NH4)2CO3 at a concentration of 10 mg/L acts as an corrosion inhibitor of steel in a 0.1 M NaCl solution, and IFKHAN-114 (nonequivalent mixture of polyaniline with benzoic acid), introduced into the solution along with this amount of ammonium carbonate, plays the role of a corrosion stimulator. However, with an increase in the concentration of ammonium carbonate, its inhibitory effect is decreased, and for IFKHAN-114, introduced along with the salt, on the contrary, is appeared. A similar pattern is observed for the copper electrode. In the presence of (NH4)2S, almost the same effect of salt and VCI is observed for steel and copper, but with some variation. A comparison of the data obtained by gravimetric tests and impedance measurements showed that in the latter case only qualitative results can be obtained, although they undoubtedly confirm the presence of the inhibitory ability of IFKHAN-114 in a chloride neutral solution.

Performance Assessment of Bolted Extended End-Plate Moment Connections Constructed from Grade St-37 Steel Subjected to Fatigue

AbstractMost studies on the bolted extended end-plate (BEEP) moment connection have focused on the rotation capacity of the connection before the yielding of the connection members takes place, and...

Cross-linked poly(N-alkyl-4-vinylpyridinium) iodides as new eco-friendly inhibitors for corrosion study of St-37 steel in 1 M H2SO4

Cross-linked poly (N-alkyl-4-vinylpyridinium) iodides abbreviated as P4-VPMI, P4-VPOI and P4-VPDI, were synthesized from quaternization of poly(4-vinyl pyridine) cross-linked with 2% DVB, by three alkyl iodides [methyl iodide (MI), octan iodide (OI) and decan iodide (DI)] in acetonitrile at room temperature. Then, their effect as new eco-friendly polymeric inhibitors was investigated in the corrosion process of St-37 in 1 M H2SO4. Formation of the inhibitors was approved by energy dispersive X-ray spectroscopy (EDS) and Fourier transform infrared spectroscopy (FT-IR) techniques. Furthermore, their inhibition performance was studied using weight loss measurements, potentiodynamic polarization (tafel), and electrochemical impedance spectroscopy (EIS). By comparison of the inhibitive behavior of three inhibitors using mentioned methods and according to the obtained results, it was clearly found that, by adding all inhibitors into the corrosive solution (1 M H2SO4) and also with increasing of the inhibitors concentration, the steel corrosion is greatly reduced. The results also showed that, inhibition efficiency (%E) was decreased by increasing the length of carbon chain of the alkyl group. Therefore among the three inhibitors, P4VPMI with a concentration of 0.04 g l−1 has the best inhibition effect on the corrosion of St-37. Furthermore, the value of $$\Delta G^{0}$$ is found to be − 30.75 kJ mol−1; probably means that the adsorption of the inhibitors on St-37 surface involves both physical and chemical adsorption.

ОСОБЕННОСТИ КАТОДНЫХ И АНОДНЫХ РЕАКЦИЙ НА УГЛЕРОДИСТОЙ СТАЛИ В ЗАВИСИМОСТИ ОТ ГЛУБИНЫ ПОГРУЖЕНИЯ В НЕЙТРАЛЬНЫЙ РАСТВОР

The investigation of the depth immersion of the specimens on corrosion rate of steel St3 in 3 % NaCl solution. Simulation of atmospheric corrosion (humid and wet) was performed by immersing of a steel sample by the size of (50×10×2) mm in a neutral solution of 3% NaCl at different depths. By leading the lower boundary of the working surface of the sample to the level of the solution (about 0 mm), humid corrosion was simulated, submerged to a depth of 2 mm (up to the upper boundary), wet corrosion, and 10 mm from the upper boundary - the electrolyte volume. The developed method allowed to carry out electrochemical researches by the method of polarization curves. The polarization curves were measured in the potentiodynamic mode with the potential scanning rate of 5∙10-4 V/s .The working electrode was a sample of steel St3 by the size (10×50×2) mm. A work surface (10×2) mm was separated on the sample, the rest of the surface was isolated with a non-conductive varnish. The results of the investigation of the effect of depth immersion of samples into electrolyte solution on corrosion rate of St3 steel are presented. The conditions of “humid” and “wet” atmospheric corrosion of the metal were simulated by the immersion of samples on a depth from 0 to 10 mm into 3% sodium chloride solution. It was found, that on the base on determination of the rate of particular electrode reactions occurring on the electrode at various depths of its immersion into the solution, the corrosion rate of steel St3 was determined by the value of the limiting diffusion current.It was shown that the value of limiting current increases from 0.51 to 2 A/m2 with decreasing of the film thickness. It has been established that the cathodic process rate depends both on the concentration of oxygen in the layers of the solution, which are at different distances from the solution/air boundary, and on the speed of its diffusion to the metal surface. Because the method of polarization resistance allows to measure the currents smaller than the currents of oxygen reduction in thin films of the solution, it can be used to estimate the rate of atmospheric corrosion of steel. Based on simulation of humid and wet atmospheric corrosion the effect of immersion depth of the specimens on the cathodic reaction rate of steel St3 in 3 % NaCl solution was established. The cathodic current density (limit diffusion current) is raised from 0,51 to 2 A/m2 under decreasing of immersion depth. The suggested method of simulation of atmospheric corrosion may be used for electrochemical investigations in thin films of moisture of different thickness which are form on the metals and sensors surfaces. The possibility of application of polarization resistance method for atmospheric conditions was presented.

Tempering of Cold-Rolled Martensite in Mild Steel and Elucidating the Effects of Alloying Elements

The martensite thermomechanical process was applied to the st37 steel and a modified version of this steel containing micro-addition of Cr and Mo. It was found that the presence of Cr and Mo can result in the retardation of softening during tempering of cold-rolled sheets, where the hardness of the modified steel at each tempering time was much higher compared to that of the st37 steel. Accordingly, the characteristic hardness fall (related to the occurrence of continuous recrystallization) was postponed effectively. The development of fine ferrite/carbide aggregate via martensite process resulted in the enhancement of tensile properties compared to the as-received ferrite/pearlite microstructure. The micro-addition of Cr and Mo was also found to be conducive to grain refinement during tempering of cold-rolled martensite.

Surface Quality Comparison of Down and Up cut Technique on CNC Milling Machine toward ST-37 Steel Material

The purpose of this research is comparing down and up cut technique on milling process toward ST-37 steel material by using HSS Ø12 mm end mill cutter. The surface roughness result of down cut technique is achieved Ra 2.39 μm which is equivalent to N7 roughness level at lowest cutting speed 20 m/mnt. Moreover, the highest roughness Ra 3.61 μm obtained at highest cutting speed 30 m/mnt which is equivalent to N8 roughness level. While, the quality of up cut technique yield the roughnes Ra 3.94 μm, equivalent to N8 roughness level at lowest cutting speed 20 m/minute, whilst, Ra 6.01 μm that equivalent to N9 roughness level on highest cutting speed condition 30 m/minute. The surface roughnes value achieved between N7-N9 level (ISO). Down cut technique is recommended in order to achieve good surface quality, because it could be generate lower surface roughness on material.
 Tujuan dari penelitian ini adalah membandingkan teknik down cut dan up cut pada proses freis terhadap material baja ST-37 dengan menggunakan end mill cutter diameter Ø12 mm. Hasil kekasaran permukaan dari teknik down cut adalah Ra 2,39 μm yang setara dengan level kekasaran N7 pada kecepatan potong terendah 20 m/mnt. Selanjutnya, kekasaran tertinggi Ra 3,61 μm diperoleh pada kecepatan potong tertiggi 30 m/mnt yang setara dengan level kekasaran N8. Sementara itu, kualitas teknik up cut menghasilkan kekasaran Ra 3,94 μm yang setara dengan level kekasaran N8 pada kecepatan potong terendah 20 m/mnt, sedangkan Ra 6,01 μm yang setara dengan level N9 pada kecepatan potong tertinggi 30 m/mnt. Harga kekasaran permukaan material diperoleh di antara level N7-N9 (nomor kekasaran ISO). Teknik down cut direkomendasikan untuk memperoleh kualitas permukaan yang baik, karena teknik ini dapat menghasilkan kekasaran permukaan yang lebih rendah pada benda kerja.

The Effect of Microstructural Imperfections on Corrosion Fatigue of Additively Manufactured ER70S-6 Alloy Produced by Wire Arc Deposition

This study aims at evaluating the effect of microstructure imperfections on the corrosion fatigue performance of an ER70S-6 alloy produced by wire arc additive manufacturing (WAAM) process, in a 3.5% NaCl solution. For reference, a regular ST-37 alloy with relatively similar chemical composition was considered as a counterpart alloy. This was justified by the fact that the ER70S-6 alloy is usually used for conventional welding of ST-37 steel. The results obtained indicated that while the ST-37 alloy exhibited fatigue strength of 240 MPa in the corrosive solution, the additively manufactured ER70S-6 alloy showed fatigue strength of only 140 MPa. These differences were related to microstructural imperfections that are inherently produced during the WAAM process.

The influence of parameters of friction stir welding modes on the mechanical properties of corrosion-resistant alloys with steel

The article discusses promising technological methods used for the formation of joints of corrosion-resistant alloys with steels by friction stir welding (FSW). The dependences of the strength characteristics modes on the FSW (angle of inclination of the tool, displacement of the tool from the contact line of the welded samples) are presented. The subject of the analysis is the design of the edges of the parts to be welded in the case of FSW and the stage-by-stage analysis of the process of producing butt joints of corrosion-resistant alloys with steels, taking into account the parameters of welding modes. The article analyzes the factors affecting the strength of dissimilar joints of OT4-1 (VT1) alloys and St3 (12H18N10T) steels, made with the help of a FSW. The influence of the geometry of the prepared edges of parts on the strength of welded joints has been studied. The results of strength tests are presented, design and technological methods are recom- mended, aimed at improving the conditions and activating the formation of adhesive dissimilar joints.

Study of the inhibitory ability of inorganic di- and polyphosphate compositions

The article considers the anticorrosive properties of inorganic di-and polyphosphate compositions in relation to St-3 steel, depending on the pH of the medium, the nature and concentration of phosphate, and the nature of the modifier ion. The research was conducted using GOST-based methods: gravimetry, potentiometry, photocolorimetry, infrared spectroscopy and scanning electron microscopy. On the basis of experimental data, quantitative indicators of corrosion process were determined: the rate of corrosion process, the degree of protection, the depth index, the coefficient of inhibition and the assessment of the stability of the formed film on the ball scale of corrosion resistance against steel. The analysis of experimental data allows to establish the influence of the above factors on the corrosion processes in the systems under study. The experimental data are supplemented by thermodynamic calculations of the corrosion process parameters, the results of which correlate well with the kinetic data of the process under study. In the course of the research work, the analysis of corrosion deposits was also carried out. The regularities established during the work contribute to the creation of effective di-and polyphosphate inhibitors with the highest degrees of protection.

Determination of the peculiarities of obtaining coatings of different hardness on structural steel at diffusion metalization

The features of obtaining coatings on carbon steel, structural steel St 3 are studied during diffusion metallization – simultaneous saturation of steel with boron, chromium and aluminum (boron chromium aluminizing), without the use of special heat treatment. The basic compositions of powder mixtures are established using the simplex lattice method, which make it possible to obtain boride structures of increased hardness, phases of a solid solution of boron, chromium and aluminum in Fe α and the predicted depth of the surface layer on the surface of carbon steel. The characteristic features of the microhardness formation of the surface layer of coatings are established depending on the composition of the saturating mixture. An important factor is established for the effect of aluminum on the microhardness of the surface layer in multicomponent systems. Its presence contributes to the formation of solid solutions. New data are obtained on the formation of surface layers during steel saturation with boron, chromium and aluminum, and the conditions for obtaining layers of high hardness and high ductility are determined. The optimal areas for the formation of coatings of various structures and depths by the simplex planning method are found. As optimization factors, let’s use the relative planes occupied by borides and solid solution, as well as the depth of the surface layers. It is clearly shown how the structure of surface layers changes depending on the quantitative relations between the components of saturating mixtures. The graphical dependences of the boride phase, the phase of the solid solution and the depth of the layer, on the composition of the saturating mixture during diffusion metallization (boron chromium aluminizing) allow to improve the process in order to obtain coatings with increased wear resistance on the surface of carbon steel

Generalized diagrams and equations of recrystallization of cold-deformed steel St

The recrystallization processes in steel St.3 inthe ferrite state were studied. Samples with diameter of 8 mmand with height of 10 mmwere deformed by compression at 20 °Cfor 20 to 80 %, annealed at 400 – 735 °Cfor a period from 5 minutes to 10 hours, and cooled in the air. On the samples, the grain size was determined in longitudinal sections (with respect to the compression axis). After separation of the entire array of experimental data (degree of deformation ε, temperature T and time τ of annealing, grain size D) into 3 groups (no recrystallization, beginning and end of the primary recrystallization), the equations of hyperplanes best sharing these groups were found by the method of discriminant mathematical analysis. Recrystallization is not observed if the temperature is below 465 °C, or if the degree of deformation is lower than 20 % for any combination of other parameters. The deformed structure completely recrystallizes if the experimental points are in the parameter range: T > 550 °C, ε > 40 %, τ > 30 min. The largest grain refinement (up to 7 – 10 μm) was obtained after deformation with a maximum degree (80 %). The first critical (physical) degree of deformation, after which the size of the recrystallized grain is larger than the original one, is absent. The second critical (technical) degree of deformation is 25 – 35 % for temperatures of 530 – 735 °C. At such degrees grain refinement was observed in comparison with the initial deformed state. Mathematical relation between the size of the recrystallized grain and the experiments’ parameters was analyzed in two ways: according to Arrhenius in the form D=AεNτMexp (-Q/RT) , and according to Hollomon with linear temperature dependence (D ~ T). The Arrhenius solution gave the following equation: log(D) = 2,08 – 0,33log(ε) + 0,023log(τ) – 967,31 1/T. Therefore, activation energy of the recrystallization process is found to be ~18,000 J/mol. In case of the Hollomon analysis, it was proposed to use the function РН = T/1000 [СН – log(τ) + log(ε)] as the Hollomon parameter, and the Hollomon constant of CH should be found by numerical methods. For these conditions, the equation D = –21,317 – 0,034T + 0,0032log(τ) T – 0,0032log(ε)T was obtained. The accuracy of both descriptions, defined as the sum of deviations squares of the measured grain sizes from calculated, is equal to ~3,3 μm or (when normalized to an average value) ~20 %.

The influence of acid and base solutions on the quenching process against the hardness of ST37 steel

Previous research stated that salt water cooling media has higher hardness value after going through the heat treatment process compared to freshwater cooling media. From this explanation, a study was conducted on the effect of using acid and alkaline solutions in the quenching process against the hardness of ST37 steel. This study uses vinegar water cooling media and soapy water. In this study several steps were carried out, namely: hardening on ST37 steel with a heating temperature of 700ºC with a holding time of 15 minutes, direct quenching with acidic cooling media (vinegar: 2.4 pH) and alkaline solution (soap water: 9.3 pH ) with a 15 minute holding time. After the heat treatment process and direct quenching on ST37 steel, Rockwell hardness was tested. From the test results, the use of acid and base solution cooling media in the quenching process has an effect on the hardness of ST37 steel, the best hardness value is an alkaline solution compared to an acid solution, alkaline solution has a hard value of 66.73 HRC, while acid solution has a hardness value of 64.31 HRC. The results of this study will be one of the references for further research, especially the use of weak acid-base solutions as a cooling medium.

Effects of Electrode Movements on Smaw Welding to The Quality of ST-37 Steel Welds

Many factors affect the welding results including electrode movement, welding current and electrode type. This study aims to determine the effects of electrode movements on SMAW welding to the quality of ST-37 steel welds. The quality reviewed includes microstructure, tensile strength, yield stress and weld defects. The study used ST 37 Steel with thickness 10 mm and a size of 100 mm x 200 mm, open V seam with an angle of 600 degree. E 7016 series electrodes had a diameter of 3.2 mm. Welding current 90-92 amperes, polarity DC +, welding voltage 25 volts and travel speed 8-10 cm / minute. Electrode movements variations include straight, zig-zag and spiral movement. The results showed that the micro structure of the Acicular Ferrite (AF) on the electrode spiral movement looks uniform, tight, dominates the area, the spiral movement of the electrode provides the highest tensile strength and the highest yield strength and the electrode spiral movement does not produce welding defects

Features of Diffusion Interaction in Steel-Aluminum Composite After Explosive Welding and Aluminizing by Melt Immersion

Diffusion interaction at an interlayer boundary of St3 steel–AD1 aluminum after explosive welding and aluminizing by melt immersion is investigated. Test heat treatment regimes are revealed providing formation of coatings based on iron aluminides on a steel surface. It is shown that in order to form Fe2Al5 intermetallic on a steel surface with the hardness of 10 GPa, an explosion welded steel-aluminum composite must be given double heat treatment. After the first (660 °С, 3 h) a two-layer (Fe2Al5 and FeAl3) diffusion zone is formed, and after the second (640 °С, 3 h) it is destroyed along a main crack between the Fe2Al5 and FeAl3 interlayers. In order to form an Fe2Al5 intermetallic coating on a steel surface an aluminized layer obtained by melt immersion must be heat treated at 800 °C. Doping the diffusion zone with Si leads to the appearance of additional phases Al7Fe2Si and (Al, Si)5Fe3 within the composition, and an increase heat treatment duration leads to a reduction in coating hardness to 7.5–8 GPa.

Thermophysical model of electron beam boriding of carbon steel St3

The work aims at developing a thermophysical model of electron-beam boriding of carbon steels. The main attention focuses on the physicochemical processes of the formation of iron borides occurring in the treatment zone by the electron beam. A thermodynamic study of phase equilibria in the systems Fe-B-C-O has been performed. On the basis of numerical calculations of temperature fields it is shown that temperature and time conditions of heating and cooling of steel determine the nature of structural transformations. Strength characteristics of iron boride layers have been determined. Then these layers obtained by different methods and using various source components have been thoroughly compared with each other during the analysis.

Ergodic Analysis of Three-Dimensional Chebyshev Spectrum of Electrochemical Noise

The ergodicity of electrochemical noise of corrosion process with respect to the three-dimensional Chebyshev spectrum is studied. The electrochemical noise of “two identical electrodes of steel St-3 in the NaCl + benzotriazole solution” corrosion system is measured. The use of the Chebyshev noise spectra in the test for the ergodicity of electrochemical noise is dictated by the fact that the intensity of the second and higher Chebyshev spectral lines is resistant to the trend of electrochemical noise. It is found that in the initial period of interaction between the electrode and electrolyte, the electrochemical noise of the corrosion process is characterized by a weak ergodicity. However, even in 2.5 h, the ergodicity test shows that the steady state is reached. A similar situation is observed for the electronic noise of measuring equipment. The test for the ergodicity of electronic noise using the second component of three-dimensional Chebyshev spectrum shows that the steady state is reached in 30 min after switching on the measuring equipment. The ergodicity test with respect to the second component of three-dimensional Chebyshev spectrum can be used for the analysis of ergodic properties of random noise of any nature even under the conditions of strong trend.

Pengaruh Sudut Potong dan Kecepatan Putaran Spindel Terhadap Kekasaran Permukaan pada Proses Bubut Mild Steel ST 37

The surface quality of turning can be influenced by several factors such as determining the spindle rotation speed, determining cutting speed (cutting speed), cut angle. the purpose of this study was to compare the level of surface roughness in the mild steel ST 37 on lathe process. Every surface of the workpiece that undergoes a machining process will experience varying degrees of roughness. This research is an experimental study that compares the level of surface roughness of material material Mild Steel ST 37. Material that is done with a length of 70 mm, and turned into a diameter of 20 mm using 3 kinds of cutting angles and 3 kinds of spindle rotation speed. Measuring the surface roughness of the workpiece, namely surface tester mitutoyo SJ-201P. The results of this study can be concluded that the spindle rotation speed of 740 rpm with 80˚ cutting angle produces a smoother surface that is (∑Rap) = 5.76 μm or in the roughness class N9 while the spindle rotation speed is 440 rpm with 80 potong cutting angle produces a surface coarse (∑Rap) = 11.47 μm with N10 surface roughness class.

Inhibition of microbial influenced corrosion on carbon steel ST37 using biosurfactant produced by Bacillus sp.

Microbial influenced corrosion that associated with biofilm has been one of the major problem in industry. It causes damage to equipment and infrastructure because of rapid material deterioration and often resulting in pipeline failures. Pipeline failures can lead to large economic losses and environmental problems. Synthetic chemical biocides are commonly used to prevent corrosion but are not effective against preformed biofilm on pipes and toxic to the environment. A new antimicrobial is being developed by using biosurfactant produced by indigenous oil reservoir bacteria Bacillus sp. to prevent and eradicate biofilm. This study aims to determine minimum inhibitory concentration (MIC), minimum biofilm inhibitory concentration (MBIC), and minimum biofilm eradication concentration for 50% eradication (MBEC50) of biosurfactant against biofilm forming bacteria isolated from oil resevoir, its effect on biofilm community structure and its ability to inhibit the corrosion rate of Carbon Steel ST37. MIC, MBIC, and MBEC50 were determined using broth macrodillution technique, biofilm community structure were analyzed using total plate count method, and corrosion rate of steel were determined using weight loss method. Biofilm and corroded steel surface was also visualized using SEM-EDS. From this study, it is revealed that MIC, MBIC, and MBEC50 values respectively are 62.5; 31.25; and 500 μg ml−1. Biosufactant is able to inhibit Pseudomonas sp. 1 and Pseudomonas sp. 2 attachment to Carbon Steel ST37 surface and also able to eradicate preformed biofilm on steel surface. This study also showed the reduction of corrosion rate in Carbon Steel ST 37 as a result of biosurfactants treatment; from 4.56 × 10−4 mm year−1 to 3.31 × 10−4 mm year−1 based on MBIC value and from 5.18 × 10−5 mm year −1 to 2.7 × 10−5 mm year−1 after biofilm eradication at MBEC value. The results showed that biosurfactant in this study could be a good candidate for a new anti-corrosion agent.