Cathodic Protection (Hindi) कैथोडिक प्रोटेक्शन क्या है #ICCP #Cathodicprotection #Sacrificialanode

00:00 Introduction about Cathodic Protection 01:30 Different topics covered in video 01:50 What is Corrosion 04:37 Factors influencing Corrosion 11:53 Types of Corrosion 13:56 Corrosion preventive Method (Cathodic Protection) 16:48 Types of Cathodic Protection (Sacrificial Anode Method and Impressed Current Cathodic Protection. TYPES OF CORROSION ● Uniform Corrosion: Uniform corrosion is the most common form of corrosion and causes the most metal loss, often leaving behind a scale or deposit. Ex:-Atmospheric Corrosion, Corrosion in Water, High Temperature Corrosion ● Non-Uniform Corrosion: Non-uniform corrosion or localized corrosive attack is a type of electrochemical corrosion. There are many types of non-uniform corrosion that occur, primarily depending on the type of the metal and the characteristics of the corrosive environment. Crevice corrosion is also a localized form of corrosion and usually results from a stagnant microenvironment in which there is a difference in the concentration of ions between two areas of a metal. Crevice corrosion occurs in shielded areas such as those under washers, bolt heads, gaskets, etc. where oxygen is restricted. PITTING CORROSION:-. Pitting is a localized form of corrosion, in which either a local anodic point, or more commonly a cathodic point, forms a small corrosion cell with the surrounding normal surface. Once a pit has initiated, it grows into a “hole” or “cavity” that takes on one of a variety of different shapes. STRESS CORROSION CRACKING Stress corrosion may result from external stress such as actual tensile loads on the metal or expansion/contraction due to rapid temperature changes. It may also result from residual stress imparted during the manufacturing process such as from cold forming, welding, machining, grinding, etc. CORROSION PREVENTION METHOD CATHODIC PROTECTION:- Cathodic Protection (CP) is one of the most effective methods for preventing most types of corrosion on a metal surface. In some cases, CP can even stop corrosion damage from occurring. Metals, especially ferrous metals, corrode in the presence of oxygen, water, and other impurities such as sulfur. Without CP, metals act as the anode and easily lose their electrons and thus, the metal becomes oxidized and corroded. CP simply supplies the metal with electrons from an external source, making it a cathode. Basic Terminology Oxidation — Loss of electrons ; Anode — Where oxidation reactions take place Reduction — Gain of electrons ; Cathode — Where reduction reactions take place TYPES OF CATHODIC PROTECTION 1. SACRIFICIAL ANODE METHOD:- When two metals are electrically connected to each other in a electrolyte e.g. seawater, electrons will flow from the more active metal to the other, due to the difference in the electrical potential. When the most active metal (anode) supplies current, it will gradually dissolve into ions in the electrolyte, and at the same time produce electrons, which the least active (cathode) will receive through the metallic connection with the anode. The result is that the cathode will be negatively polarized and hence be protected against corrosion. IMPRESSED CURRENT CATHODIC PROTECTION (ICCP) The positive DC output terminal is connected via cables to the array of anodes buried in the ground. A cable connects the negative terminal of the rectifier to the pipeline to be protected. The operating output of the rectifier is adjusted to the optimum level.