WITH WITNESSING THE INCREASE OF MARINE INDUSTRY, COPPER AND ITS ALLOYS ARE WIDELY USED IN MANY MARINE-RELATIVE ENVIRONMENTS AND ENGINEERING APPLICATIONS OWING TO THEIR EXCELLENT PROPERTIES, SUCH AS ELECTRICAL AND THERMAL CONDUCTIVITY, MECHANICAL WORKABILITY AND ITS RELATIVELY NOBLE PROPERTIES. HOWEVER, IN THE PRESENCE OF THE NEUTRAL CHLORIDE MEDIA, THEY ARE MUCH SUSCEPTIBLE TO CORROSION, LEADING TO ENORMOUS ECONOMIC LOSSES AND MANY POTENTIAL SAFETY PROBLEMS. ONE OF THE MOST EFFICIENT APPROACHES FOR PROTECTING COPPER AGAINST AGGRESSIVE ATTACK IS THE USE OF THE NATURAL ORGANIC COMPOUNDS TO FORM TIGHT FILMS WHICH CONTAIN ELECTRONEGATIVE FUNCTIONAL GROUPS AND P-ELECTRON IN TRIPLE OR CONJUGATED DOUBLE BONDS [1-4]. THE ADSORPTION AND CORROSION PROTECTION EFFECT OF ACORUSCALAMUS (AC) ON THE COPPER SURFACE IN 3 WT% NACL SOLUTION WAS INVESTIGATED USING POTENTIODYNAMIC POLARIZATION AND ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY (EIS). POLARIZATION CURVES INDICATE THAT AC IS A MIXED INHIBITOR, AFFECTING BOTH CATHODIC AND ANODIC CORROSION CURRENTS. THE INHIBITION EFFICIENCY OF AC REACHED 98% AT AN OPTIMIZED CONDITION.

NATURAL WATERS DUE TO EVAPORATION TO LEAVE DEPOSITS THAT INBOILERS BE CAUSING PROBLEMS. THIS PROBLEM IN, STOPPING THE SYSTEM AND THE NEED TO REPLACE PARTS RESULT IN INCREASED VARIOUS COSTS. IN THIS STUDY, DEPOSITION AND CORROSION IN BOILERS BEEN CHECKED. ALSO OFFERED GUIDELINES TO MAINTAIN THE BOILERS.

OLEYL HYDROXYETHYL IMIDAZOLINE (OHI) HAS BEEN SYNTHESIZED AS CORROSION INHIBITOR BY REACTING METHYL OLEATE AND N- (2-HYDROXYETHYL) ETHYLENEDIAMINE. THE H2S CORROSION INHIBITION OF X-120 PIPELINE STEEL BY USING THE INHIBITOR HAS BEEN EVALUATED BY ELECTROCHEMICAL TECHNIQUES INCLUDE POTENTIODYNAMIC POLARIZATION METHOD AND ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY. TESTING SOLUTIONS INCLUDE H2S-CONTAINING 3.5% NACL WITH DIFFERENT CONCENTRATIONS OF INHIBITOR (0, 25, 50, 100, 200 AND 400 MMOL L-1) AT 50 OC. RESULTS SHOWED THAT BY ADDING 200 MMOL L-1 OF THE INHIBITOR BOTH UNIFORM AND LOCALIZED CORROSION DECREASES. THE LOWEST CORROSION RATE IS OBTAINED WITH 200 MMOL L-1 OF THE INHIBITOR, ALTHOUGH A SIGNIFICANT REDUCTION IN THE CORROSION RATE IS REACHED WITH THE ADDITION OF 100MMOL L-1 OF THE INHIBITOR, OBTAINING AN ICORR VALUE OF 140 NA CM-2. THE CHANGE IN THE RP VALUES WITH TIME FOR X-120 STEEL IN THE H2S-CONTAINING 3.5% NACL SOLUTION AS A FUNCTION OF THE INHIBITOR CONCENTRATION IS MEASURED. THE RESULTS SHOWED THAT ALL THE RP VALUES DECREASE WITH TIME, EXCEPT THAT FOR 200 MMOL L-1 OF OLEYL HYDROXYETHYL IMIDAZOLINE.

CORROSION INHIBITORS IN MILD STEEL PLAY A FAIRLY IMPORTANT ROLE IN MILD STEEL DIFFERENT APPLICATION. STAINLESS STEELS ARE DESIGNED FOR APPLICATIONS IN AGGRESSIVE OIL FIELD AND MARINE ENVIRONMENTS WHERE BOTH CORROSION RESISTANCE AND MECHANICAL PROPERTIES OF STAINLESS STEELS WOULD PERHAPS BE LIMITED [1]. HYDROCHLORIC ACID SOLUTION CAUSES CORROSION OF STAINLESS STEEL [2]. ....