CHEMICAL CONTENTS AND FOUNDRY CHARACTERISTICS OF DARAZO SAND DEPOSIT
R.I.Ejilah1 , E.I. Onuh1 , S. Datau1and J.S. Jatau2
The torsional characteristics of NST 44-2 low carbon steel have been determined. The low carbon steel was subjected to the following post-weld heat treatment (PWHT) operations: annealing, quenching, normalizing, and tempering, and compared with un-heat treated as-welded low carbon steel with regard to their modulus of rigidity, maximum shear stress, torsional strength, torsional rigidity, torsional spring constant, and angle of twist. Four samples were used for each heat treatment operation. The results obtained showed that annealed, normalized and as-weldedspecimens displayed the lowest modulus of rigidity (2.14*106 N/mm2, 2.15*106 N/mm2, and 2.78*106 N/mm2), torsional rigidity (1.68*104N-mm2, 1.68*104 N-mm2, 2.19*104 N-mm2), and torsional spring constant (3.62*106 , 3.64*106 , 4.72*106); and a higher unit angle of twist was observed for the annealed and normalized specimens (0.23 rad/mm, 0.23 rad/mm) respectively. The, torsional strength (42.42 mm3) of tested specimens remained unaffected by PWHT operations. The study shows that better torsional behaviour of welded low carbon steel materials is obtained by post weld annealing and normalizing operations.