Title: STUDIES ON WEAR BEHAVIOUR OF STEELS USED FOR CROP CUTTING BLADES IN AGRICULTURAL MACHINERY
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Date
2020-01-02
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Publisher
Publisher : Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola, Maharashtra.
Abstract
Abstract: Steel is a widely used material for most of the engineering applications not only because of its availability in market but also because of its attaining a wide range of properties, such as hardness, strength, toughness, wear resistance etc., which is not found in any other family of materials ( Agrawal, 1988). Steel is used basically in two ways (i.e. un-treated and treated) for various applications. Untreated steels have low level of mechanical and tribological properties whereas treated steels with proper combinations of soaking time, austenitizing temperature and transformation rate provide desired properties as per applications/use. The treated steels are single, dual and multiple phasic. Properties of dual phase steels, such as ferrite – martensite, suit the requirement of agricultural implements as it possess good combination of ductility, strength, toughness and better deformability than other high strength steels (Jha,et al. 2003). These steels exhibit other inherent specific material properties like, corrosion, wear resistance and machinability. Therefore, high strength low alloy dual phase steels are typically used in different engineering applications like power generation equipments, railways, pressure vessels, automobiles, reinforcing rods and bars, welded structure and agricultural applications particularly fast wearing components, like the brake and clutch linings, gears, bearings and crop cutting blades etc.
Generally, carbon is the most important element profoundly affecting the mechanical properties of the steels. Increasing the carbon content of steels increases the hardness and strength. More -over, plain carbon steels have moderate strengths and can resist satisfactorily ordinary temperatures range 20º to 60ºC and atmospheres RH 90% and also are available in large quantities, in quite large variations of shapes and sizes with much lower cost.
In their service periods, steels parts undergo heavy working due to crop residue stresses. As a result wearing and tearing or breakage take place due to gradual loss of material during working of the component. The quality of the steel products depends on the condition of their surfaces and on surface deterioration due to use. Surface deterioration is also important in engineering practice, it is often the major factor limiting the life and performance of machine components.
Various types of steels are used in agricultural applications. In most of farm tools and implement machinery steel is about of 80 to 90 per cent of the entire body weight. Presently, low carbon steels especially mild steels are being used for making many farm tools and implements. Medium carbon steels, high carbon steels and some low alloy steels are also being used for fast wearing components of farm implements/machines to provide high strength, toughness and wear resistance. Based on survey of manufacturers of fast wearing components of agricultural implements, it is revealed that majority of manufacturers were using medium carbon steel (55%) followed by high carbon steel (27%), mild steel (12%) and high carbon tool steel (6%) (Singh and Saxena, 2005).
Experimental procedure adopted for estimating the quantity of wear loss and wear rate of power operated chaff cutter blade. The experimental procedure followed for conducting the different experiments has also been discussed. Experiments were conducted in three different phases to achieve the objectives of the proposed research work. In first phase market survey was done for collection of different materials used for manufacture of crop cutting blades and chemical analysis for identification of selected steel materials. In second phase, three surface hardening processes were selected and third phase, fabricated blade was done for power operated chaff cutter using best material found in phase second.
On the basis of survey, crop cutting blades of medium carbon steels (EN 8), medium carbon low alloy steels (EN 19), spring steel (EN 45) and bearing steel (EN 31) were selected as these are cost effective and readily available in all shapes and dimensions. These are heat treatable, weldable, machinable and forgeable steel. The available automobile leaf spring steels and high carbon steel strips are manufactured by blacksmith industries in India. These types of crop cutting blades are generally used for various agro-implements. Therefore, in present study these four types of steel were selected for assessment of the wear loss or wear rate of crop cutting blades. Crop cutting blades were surface hardened with different process to find out the most effective process for wear resistance. In present study, hardened and tempered, CrN coating and cryogenic treatments were selected as a surface hardening treatment.
On the basis of survey, crop cutting blades of medium carbon steels (EN 8), medium carbon low alloy steels (EN 19), spring steel (EN 45) and bearing steel (EN 31) were selected as these are cost effective and readily available in all shapes and dimensions. These are heat treatable, weldable, machinable and forgeable steel.
Wear loss was increased with increased load. All heat treatments behaved in similar manner but control sample wear loss was rapidly increased after 60 N load in EN 45. In EN 8, control and hardening and tempering wear was decreased up to 60 N load, then constant up to 65 N and after 65 N, wear loss rapidly increased with increased load. Among the steels that were studied in the research, EN 45 spring steel with CrN coating was selected to observe performance of the power operated chaff blade in field for cutting agricultural crops. It was observed that the lowest wear loss was exhibited by chaff cutter blade while cutting maize whereas highest wear loss was seen in sugarcane after 45 h. This clearly noted that, life of blade can be well decided by the type of steel selected and type agricultural feedstock.
Description
Description: The present research was carried out to find out effect of heat treatment processes on wear behavior of crop cutting blade steels under varying load and speed in laboratory. The crop cutting blade that gives minimum wear rate was selected and performance was observed on power operated chaff cutter
Keywords
Agrotags: Agricultural Engineering, Farm Power and Machinery, Heat Treatment, Agricultural Machinery, Metallurgy and Material Science,
Citation
Citation: BASTEWAD, TULSHIDAS BALIRAM. (2020). Studies on wear behaviour of steels used for crop cutting blades in agricultural machinery. Department of Farm Power and Machinery, Dr. Panjabrao Deshmukh Krishi Vidyapeeth. Ph. D. 2019. Print. xix, 154p. (Unpublished).