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The author has focused on the corrosive effect of 0.14% carbon steel in the occurrence of several amounts of soluble Sulfonated Polystyrene (SPS) and was found to be best efficient on soft iron exterior at 100ppm concentration in 0.5M hydrochloric acid assortment at 298K heat during 3h of time in this paper. The examination was performed by studying the weight loss of mild steel by varying different parameters like mixture concentration, time, and solution temperature. The efficiency of SPS was observed to rise with an increase of 91.90% of an inhibitor in the acid solution. The mechanism of physical adsorption was studied to the initiation and permitted dynamics for the reaction of altitude and extracted taking place towards the exterior of the iron sample in endothermic, impulsive and dependable through the Langmuir isotherm adsorption. Anodic and cathodic both type of nature of soluble SPS was studied using the potentiodynamic polarization method. The AFM analysis was used to do the surface and protective film analysis and under varied settings, SPS polymer inhibitor proven to be more suited for iron metal exterior.

Primjenom polarizacijskih metoda i elektrokemijske impedancijske spektroskopije ispitana je mogućnost inhibicije korozije 5052 aluminijske legure (AlMgCr) pomoću askorbinske kiseline (u granicama od 110 -6 do 110 -2 M) u 0.5 M NaCl otopini pri 20 o C. Određeni su korozijski potencijali, korozijska struja, polarizacijski otpor, otpor prijenosu naboja, kapacitet površinskog sloja i difuzija kroz površinski sloj. Izračunata je pokrivenost površine molekulama inhibitora te djelotvornost inhibicije korozije. Dobiveni rezultati su pokazali da askorbinska kiselina učinkovito usporava koroziju AlMgCr legure u kloridnoj otopini uz djelotvornost od  92 %. Nadalje, ustanovljeno je da askorbinska kiselina pripada miješanom tipu inhibitora s pojačanim utjecajem na anodnu reakciju. Mehanizam adsorpcije ispitivanog inhibitora opisan je Frundlichovom adsorpcijskom izotermom. Dobivena vrijednost za standardnu slobodnu energiju adsorpcije u iznosu ≈ -10 kJ mol -1 ukazuje na fizikalnu adsorpciju askorbinske kiseline na površinu AlMgCr legure u NaCl otopini. The corrosion inhibition performance of the ascorbic acid (in range from 110 -6 to 110 -2 M) on 5052 aluminium alloy (AlMgCr) corrosion in neutral 0.5 M solution at 20 o C was investigated using potentiodynamic and electrochemical impedance spectroscopy measurements. Corrosion potential, corrosion current, polarization resistance, charge transfer resistance, capacity of surface layer, and diffusion through the surface layer were determined. The surface coverage of the inhibitor molecules and inhibition efficiency were calculated. The obtained results show that ascorbic acid effectively inhibited the corrosion reaction of AlMgCr alloy in the chloride solution with an inhibition efficiency of up to  92 %. Furthermore, ascorbic acid was found to function essentially as a mixed type with a higher influence on anodic reaction. The adsorption behaviour of investigated inhibitor can be described by the Frundlich adsorption isotherm. The adsorption free energy closes to -10 kJ mol -1 indicates physical adsorption of the ascorbic acid on AlMgCr aluminium alloy surface in NaCl solution.

Utjecaj toplinske obrade legure CuAlMn na korozijsko ponašanje u 0,1 %, 0,9 % i 1,5 % otopini NaCl ispitan je elektrokemijskim metodama kao što su mjerenje potencijala otvorenog strujnog kruga, metodom linearne i potenciodinamičke polarizacije. Nakon polarizacijskih mjerenja elektrodna površina je ispitana optičkim mikroskopom te je provedena i SEM/EDS analiza. Rezultati ispitivanja su pokazali da toplinski obrađeni uzorci pokazuju nešto pozitivniju vrijednost potencijala u odnosu na lijevani uzorak. Povećanjem koncentracije kloridnih iona dolazi do stabilizacije potencijala pri nešto negativnijim vrijednostima za sve ispitivane uzorke CuAlMn. Gustoća korozijske struje nešto je manja, a polarizacijski otpor veći za toplinski obrađene uzorke u odnosu na uzorak lijevane legure bez toplinske obrade. Na mikroskopskim snimkama površine nakon polarizacijskih mjerenja se može vidjeti hrapava površina elektroda uslijed odvijanja korozijskih procesa. Povećanje koncentracije elektrolita dovodi do povećanja oštećenja površine elektroda. Ispitivanja pretražnom elektronskom mikroskopijom pokazala su da je površina prekrivena isprekidanim slojevima korozijskih produkata, kao i pukotinama i kanalićima koji su nastali njihovim otapanjem. Elementarna analiza površine metodom energetski disperzivne rendgenske spektroskopije pokazala je da se korozijski produkti sastoje od aluminijeva i manganova oksida i klorida čiji se postotak razlikuje u ovisnosti od mjesta na kojoj je provedena analiza. Značajno manji sadržaj bakra na površini nađen je na površini kaljenog uzorka CuAlMn legure u odnosu na površinu uzorka lijevane CuAlMn legure bez toplinske obrade. The influence of heat treatment of CuAlMn alloy on corrosion behavior in 0.1%, 0.9% and 1.5% NaCl solution was studied by electrochemical methods such as measuring the open circuit potential, linear and potentiodynamic polarization. After polarization measurements the electrode surfaces was examined by optical microscope and also with SEM/EDS analysis. The results of the investigations have shown that the heat treated samples have a slightly more positive values of the open circuit potential compared to the as cast sample. Concentration increasing of chloride ions results in potential stabilization at slightly negative values for all CuAlMn alloy samples. Values of the corrosion current density are slightly smaller and the polarization resistance values are higher for the heat treated samples compared to the sample of as cast alloy without heat treatment. The microscopic analysis of the electrode surfaces after the polarization measurements, have show the rough surfaces due to corrosion processes. Increasing the electrolyte concentration leads to an increase in electrode surface damage. Examination by scanning electron microscopy showed that the surface was covered with interlaced layers of corrosion products, as well as cracks and ducts formed by their dissolution. Elemental surface analysis by energy dispersive X-ray spectroscopy showed that corrosive products consist of aluminum and manganese oxides and chlorides, the percentage of which differs depending on the site where the analysis was performed. Significantly lower copper content on the surface was found on the surface of the annealing CuAlMn alloy sample surface relative to the surface of the cast CuAlMn alloy without heat treatment.

Korozijsko ponašanje CuAlMnTi traka dobivenih brzim hlađenjem ispitano je u 0,9% NaCl otopini pri temperaturama10, 24, 37 i 50 o C. Također je ispitan i utjecaj pH vrijednost elektrolita na koroziju traka CuAlMnTi legure u 0,9 % NaCl otopini pH vrijednosti 3,4, 5,4 i 7,4. Mjerenja su provedena elektrokemijskim metodama kao što su praćenje potencijala otvorenog strujnog kruga, metodama linearne i potenciodinamičke polarizacije. Rezultati ispitivanja su pokazali da povećanje temperature elektrolita i sniženje pH vrijednosti dovodi do negativiranja vrijednosti korozijskog potencijala, porasta gustoće korozijske struje i smanjenja vrijednosti polarizacijskog otpora što ukazuje na veći korozijski napad na CuAlMnTi leguru. Na snimkama površine koje su dobivene svjetlosnim mikroskopom vidljiva su oštećenja površine uslijed korozijskog procesa, koja se povećavaju s povišenjem temperature elektrolita i sniženjem pH vrijednosti otopine. Jamičasta korozija vidljiva je nakon polarizacijskog ispitivanja pri 50 o C. SEM snimke su potvrdile negativan utjecaj povišenja temperature i sniženja pH vrijednosti elektrolita na koroziju CuAlMnTi legure. EDS analizom utvrđena je prisutnost svih legirnih elemenata na površini, ali se njihov postotak smanjuje osobito sniženjem pH vrijednosti elektrolita. Bakar i aluminij se najprije otapaju s površine a zatim mangan, dok se postotak Ti značajnije ne mijenja uslijed korozijskih procesa što potvrđuje njegovu izrazitu korozijsku otpornost. The corrosion behavior of CuAlMnTi alloy ribbons obtained by rapid cooling was assayed in 0.9% NaCl solution at temperatures of 10, 24, 37 and 50 o C. The influence of different pH value of electrolyte on corrosion of CuAlMnTi alloy ribbons in 0.9% NaCl (pH = 3.4, 5.4 and 7.4) was also investigated. Measurements were performed by electrochemical methods such as monitoring the open circuit current potential, linear and potentiodynamic polarization methods. The results of the measurements have shown that the increase in temperature of the electrolyte and the decrease of pH value leads to a change of corrosion potential values in negative direction, a rise in corrosion current density values, and a decrease in polarization resistance values, indicating a higher corrosion attack on CuAlMnTi alloy. Surface images obtained by a light microscope show surface damages due to the corrosion process, which are increased by elevation of the electrolyte temperature and by lowering the pH of the solution. Pitting corrosion is visible after a polarization test at 50 o C. Results of SEM investigations confirmed the negative influence of temperature elevation and lower electrolyte pH on CuAlMnTi alloy corrosion. By EDS analysis, the presence of all alloying elements on the surface was determined, but their percentage decreased, especially by lowering the pH of the electrolyte. Copper and aluminum first dissolve from the surface and then manganese, whereas the percentage does not significantly change due to corrosion processes, which confirms its marked corrosion resistance.

The resistance of X5CrNi18-10 stainless steel to pitting corrosion in a solution containing chlorides and sulphates was tested using the potentiodynamic polarization method. The obtained results show that the stainless steel is significantly resistant to pit formation, but it is susceptible to pit growth and crevice corrosion. Pits formed at the corrosion potential grow continuously. Statistical analysis of the results obtained during pitting corrosion testing was performed. It can be assumed with a probability of 95% that values of indicators of resistance to pit formation (the pitting potential Epit, the metastable pitting potential Empit and the difference Epit-Ekor) will be within the range of several percents. Values of indicators of resistance to pit growth (the amount of charge required for the pit growth q, the protective potential Eprot and the difference Epit-Eprot) will be within the broader range. In addition, the appearance of pits on the surface of the stainless steel, as well as the appearance of the pits bottom, were analyzed. It was shown that the structure of the stainless steel tested was not sensitized to pitting and intergranular corrosion, which means that the stainless steel was not previously thermally treated. Primenom potenciodinamičke metode ispitana je otpornost nerđajućeg čelika X5CrNi18-10 na piting koroziju, u rastvoru koji sadrži hloride i sulfate. Dobijeni rezultati pokazuju da je nerđajući čelik u značajnoj meri otporan prema formiranju pitova, ali postoji sklonost prema rastu pitova i koroziji u zazorima. Pitovi formirani na korozionom potencijalu nastavljaju stabilno da rastu. Izvršena je statistička analiza rezultata dobijenih pri ispitivanju piting korozije. Pokazano je da će se sa verovatnoćom od 95 % vrednosti pokazatelja otpornosti nerđajućeg čelika prema formiranju pitova (potencijal pitinga Epit, potencijal metastabilnog pitinga Empit i razlika Epit-Ekor) nalaziti u granicama od nekoliko procenata. Vrednosti pokazatelja otpornosti nerđajućeg čelika prema rastu pitova (količina naelektrisanja potrebna za rast pitova q, zaštitni potencijal Eprot i razlika Epit-Eprot) će se nalaziti u širim granicama. Pored navedenog, analiziran je izgled pitova na površini nerđajućeg čelika, kao i izgled dna pitova. Pokazano je da struktura ispitivanog nerđajućeg čelika nije senzibilizovana prema piting i interkristalnoj koroziji, odnosno da nerđajući čelik nije bio prethodno termički tretiran.

The resistance of X5CrNi18-10 stainless steel to pitting corrosion in a solution containing chlorides and sulphates was tested using the potentiodynamic polarization method. The obtained results show that the stainless steel is significantly resistant to pit formation, but it is susceptible to pit growth and crevice corrosion. Pits formed at the corrosion potential grow continuously. Statistical analysis of the results obtained during pitting corrosion testing was performed. It can be assumed with a probability of 95% that values of indicators of resistance to pit formation (the pitting potential Epit, the metastable pitting potential Empit and the difference Epit-Ekor) will be within the range of several percents. Values of indicators of resistance to pit growth (the amount of charge required for the pit growth q, the protective potential Eprot and the difference Epit-Eprot) will be within the broader range. In addition, the appearance of pits on the surface of the stainless steel, as well as the appearance of the pits bottom, were analyzed. It was shown that the structure of the stainless steel tested was not sensitized to pitting and intergranular corrosion, which means that the stainless steel was not previously thermally treated.