Title of Invention | A METHOD FOR SELECTION OF ECONOMIC GRADE OF STEEL IN SUGAR INDUSTRY TO AVOID CORROSION AND OPERATIONAL BREAK DOWN |
---|---|
Abstract | The present invention relates to a method for selection of economical grade of steel pipe in sugar industry by analyzing various different grades of steel pipes (A,B,C,D,E,F) to get a comparative assessment of their performance in relation to corrosion resistance in sugar cane juice by electrochemical Tafel extrapolation technique the method comprising the steps of collecting of different grades of steel pipes (A,B,C,D,E,F) and generating of corrosion rate data by experiment of all the grades by carrying out Tafel polarization experimentations and plotting corrosion rates data obtained by extrapolarisation in a graph having zero current potential in x-axis and potential level of different grade for initiation of corrosion in y-axis and selecting the economical steel pipe which have less susceptible to corrosion (2nd maximum among all the metals as 1st maximum is costly one). |
Full Text | FIELD OF THE INVENTION The present invention relates a method of selection of steel grade for pipe of Sugar Industry. More particularly, the present invention relates to a method for selection of economic grade of steel pipe adaptable in sugar industry to avoid unwanted operational breakdowns caused by corrosion. BACKGROUND OF THE INVENTION In India, the sugar Industries are operated in a span of about 6 to 8 months in a year and any sudden occurance of operational failure during this small span causes severe loss in the productivity of sugar products. It is identified that one of the main causes of operational failure takes place in sugar Industries is the leakage occurance of steel pipe due to corrosion. The existing steel pipe is made of IS: 10748 grade I as per Indian standard IS: 1239 having a chemical composition 0.04%C and 0.2-0.3% Mn in various thickness ranging from 3 to 6mm. OBJECTS OF THE PRESENT It Is therefore, an object of the present invention to propose a method for selection of economical grade of steel pipe adaptable In sugar industry which eliminates the adversity of prior art. Another object of the present invention Is to propose a method for selection of economical grade of steel pipe adaptable in sugar industry which Is hygienic for carrying sugar cause juice in sugar Industry. A further object is to propose a method for selection of economical grade of steel pipe adaptable in sugar industry which avoids unwanted operational breakdown caused by corrosion A still further object is to propose a method for selection of economical grade of steel pipe adaptable in sugar industry which increases the productivity of sugar cause juice An yet further object is to propose a method for selection of economical grade of steel pipe adaptable in sugar industry which is cost effective. SUMMARY OF THE INVENTION To simulate actual service condition, accelerated corrosion studies were carried out over various grades of steel pipes at ambient temperature in pure fresh sugar cane juice. The methodology consists of analyzing various different grades of steel pipe for corrosion resistance in sugar cane juice. The grades of steel studied and their sample conditions are describes below: All the above mentioned grades were analysed to get a comparative assessment of their performance is sugar cane juice. The Tafel extrapolation technique was used to obtain the result of the experiment. The pH value of the sugar cane juice was measured before and after each set of experiment. The change in pH value before and after each set of experiment was not significant which ensured the freshness (almost no fermentation) of the sugar cane juice RESULT The samples were analysed for accelerated corrosion test by electro chemical method. In order to judge material performance in actual corrosion atmosphere, the tests were carried out in fresh sugar cane juice at ambient temperature. Tafel polarization experimentations were carried out for calculating corrosion rates of all grades. To determine the corrosion rate from Tafel plot, cathodic and anodic polarization is extrapolated to corrosion potential. The point of intersection of extrapolated lines corresponds to current density for metal dissolution ie, corrosion rate. The comparative Tafel plots of all the grade studied have been shown in figure- 1. The zero current potential with respect to reference electrode for different grades are listed in Table - 1 in decreasing order. The corrosion rates obtained by extrapolations have been tabulated in Table 2 in increasing order. Table 1: Zero Current Potential with respect to reference electrode for different grades (in decreasing order). Table 2: Corrosion rate of various grades I sugar cane juice (in increasing order). BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING Figure-1- Shows the Tafei plot of various grades in sugar cane juice indicating comparative potential level of different grade for initiation of corrosion. INVENTION Figure-1- Shows the corrosion rate of various grade In sugar cane Juice. The figures shows log current density (A/cm2) along the x-axis and potential (v) vs Eref in y-axis. Tafel plot of various grades in sugar cane Juice indicating comparative potential level of different grade for initiation corrosion. From figure-1, the Tafel plot Indicates that the stainless steel (F) is the most passive (-230.7) with respect to initiation of corrosion followed by cu- fi/ bearing grade (C) shown in Table 1 / As far as material dissolution rate in sugar cone juice is concerned, the lowest rate is indicated by stain less steel followed by corten and cu- bearing steel increasing order (Table-2) As shown in Table, 2 and based on combination of stainless steel (F) cu bearing steel (C) and corten steel (B) cu-bearing grade steel (C) appears to be the most economical grade to replace existing grade (IS: 10478 and grade-1) the expected service life with cu-bearing grade (C) is expected to be 25% more compared to existing grade. The higher corrosion rate of GI (D) corresponds to higher dissolution rate of zinc and possibility of contamination of sugar cane juice. WE CLAIM 1. A method for selection of economical grade of steel pipe in sugar industry analyze on various different grades of steel pipes (A,B,C,D,E,F) to get a comparative assessment of their performance in relation to corrosion resistance in sugar cane juice by electrochemical Tafel Extrapolation technique the method comprising the steps of: - collecting of different grades of steel pipes (A,BfCfDfE,F); - generating of corrosion rate data by experiment of all the grades by carrying out Tafel polarization experimentations; - plotting corrosion rates data obtained by extrapolarisation in a graph having zero current potential in x-axis and potential level of different grade for inflation of corrosion in y-axis; - selecting the economical steel pipe which have less susceptible to corrosion (2nd maximum among all the metals as 1st maximum is costly one); characterised in that the said economical grade steel pipe in sugar industry minimizes the maintenance cost due to replacement and repair of equipments due to corrosion abrasion. 2. The method as claimed in claim 1, wherein a comparative assessment of performance of different grades of steel pipe was carried out in which the pH value of the sugar cane juice was measured before and after each set of equipment. 3. The method as claimed in claim 1, wherein Tafel polarization experiments were carried out for calculating corrosion rate of all grades from Tafel plot, cathoidic and anodic polarization is extrapolated to corrosion potential by the point of inter section line corresponds to current density for metal dissolution i.e. corrosion rate. 4. A method for selection of suitable and economical grade of steel pipe in sugar industry as substantially described and illustrated herein with reference to accompanying drawings. The present invention relates to a method for selection of economical grade of steel pipe in sugar industry by analyzing various different grades of steel pipes (A,B,C,D,E,F) to get a comparative assessment of their performance in relation to corrosion resistance in sugar cane juice by electrochemical Tafel extrapolation technique the method comprising the steps of collecting of different grades of steel pipes (A,B,C,D,E,F) and generating of corrosion rate data by experiment of all the grades by carrying out Tafel polarization experimentations and plotting corrosion rates data obtained by extrapolarisation in a graph having zero current potential in x-axis and potential level of different grade for initiation of corrosion in y-axis and selecting the economical steel pipe which have less susceptible to corrosion (2nd maximum among all the metals as 1st maximum is costly one). |
---|
01095-kol-2006-correspondence-1.1.pdf
01095-kol-2006.correspondence others.pdf
01095-kol-2006.description(complete).pdf
1095-kol-2006-correspondence.pdf
1095-kol-2006-examination report.pdf
1095-kol-2006-granted-abstract.pdf
1095-kol-2006-granted-claims.pdf
1095-kol-2006-granted-description (complete).pdf
1095-kol-2006-granted-drawings.pdf
1095-kol-2006-granted-form 1.pdf
1095-kol-2006-granted-form 2.pdf
1095-kol-2006-granted-specification.pdf
1095-kol-2006-petition under rule 137.pdf
1095-kol-2006-reply to examination report-1.1.pdf
1095-kol-2006-reply to examination report.pdf
Patent Number | 247588 | ||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Indian Patent Application Number | 1095/KOL/2006 | ||||||||||||||||||
PG Journal Number | 17/2011 | ||||||||||||||||||
Publication Date | 29-Apr-2011 | ||||||||||||||||||
Grant Date | 26-Apr-2011 | ||||||||||||||||||
Date of Filing | 18-Oct-2006 | ||||||||||||||||||
Name of Patentee | TATA STEEL LIMITED | ||||||||||||||||||
Applicant Address | RESEARCH AND DEVELOPMENT AND SCIENTIFIC SERVICES DIVISION, JAMSHEDPUR | ||||||||||||||||||
Inventors:
|
|||||||||||||||||||
PCT International Classification Number | C21D 8/00 | ||||||||||||||||||
PCT International Application Number | N/A | ||||||||||||||||||
PCT International Filing date | |||||||||||||||||||
PCT Conventions:
|