SHAPE FACTOR ANALYSIS OF ABRASIVE PARTICLES USED IN SLURRY ABRASION TESTING

The engineering components are subjected to surface damage by slurry abrasion such as transportation pipes carrying ore and mineral slurries, extruders, sand pumps and agitators, Apart from stress, abrasive particle hardness, slurry concentration, particle size and shape significantly influences slurry abrasion rate. The effect of abrasive particle shape on slurry abrasion behaviour of steels and cast irons which are widely used for wear protection has not been studied. The particle shape assumes significant importance due to fracture and fragmentation of the particles during the process of abrasion. In the present work, the particle shape characterization of silica sand abrasive particles was carried by shape factor analysis using image analysis technique. An attempt was made to correlate the different measures of shape factor with particle size of abrasive particles over a wide range. The characterization of slurry abrasion tester was carried out using slurry abrasion tester with silica sand slurry. The effect of sliding distance on slurry abrasion volume of mild steel was studied. The volume loss increased linearly with sliding distance. The scanning electron microscopic observations of worn our surfaces showed micro-ploughing and cutting as mechanism of material removal

Thermomechanical processing of low carbon, IF and IF high strength steels - A few typical cases

Steel is one of the engineering materials for automobile industries. It constitutes about 60% of the weight of a typical car body. During last two and a half decades, the steel industry has undertaken the development and stable mass production of high performance, high quality steel sheets as demanded by the automobile industries. The principal properties of interest in steel sheets are strength, ductility, formability. and weldability. The control of tinal microstructure begins during solidification and proceeds during reheating, hot rolling and final transformation. Most of the steel sheets used in the autobody are in !.;old rolled and annealed condition in order to induce strength and desired crystallographic structure for formability. The hot band properties greatly atfect the finishing properties of cold rolled annealed temper rolled steel sheets. The paper discusses a few typical cases of Low carbon, Interstitial free and Interstitial free-high strength steels, elucidating the effect of thermomechanical processing on mechanical properties. (/nd Interstitial free-h igh strength