ملخص البحث :

Abstract. Dynamic shafts subjecting to salty rain water, especially in places with no rain water drainage networks, is undesirable because this media causes corrosion of the parts of shaft that increases as increasing of shaft immersion in a salty media (NaCl) also, increasing of concentration which in turns reducing number of operation runs. Increasing salt concentration from 3% to 6% NaCl results in decreasing of operation runs from 25600 to 17100 runs. Also, increasing salt concentration leads to raise the effect of alternating stress that makes strain hardening factor drop to 0.45 and ratio of dynamic shear stress to static one raise to 2.44 that affects shaft metal performance to resist fatigue. Samples were also, treated by oxy acetylene surface hardening and were cooled by immersion in oil then immersion in 6% NaCl salty solution, the results showed that number of operation runs before failure had increased up to 71022, the effect of alternating stress had decreased down to 6100 N/m2 , surface strain hardening factor had increased up to , also ratio of dynamic shear stress to static one had decreased down to 0.839. This is a good indicator of the effectiveness of surface hardening process of shaft parts that subject to salty rain water during maintenance operations.

ملخص البحث :

The present paper shows the study of punch cross section difference ( circular, square, ellipse, hexagon) effect on piercing process performance by impact to know any cross section have high stress which effect on cutting tool root, and then can be avoid high stress by changing of cross section punch or by using quality superlative lubricant approaches to attain sustainable development in keep on employment of tool and artifacts in manufacturing processes. Traditional cutting equations are used to calculate shearing cutting forces to perform process. The high value was for ellipse punch cross section (33681N) because of splaying which increase of punch penetration shear area. The longitudinal vibration equation is used to produce shear cutting forces values. The results were in same direction for ellipse punch cross section (35199 N), and the hexagon and square cross section record values are closed to the ellipse because of sharp edges for punch cross section. The strain gage technique is used practically to record cutting tool strain values, and the ellipse punch shape gives maximum value of strain (0.00367) and maximum value of shear stress (382MPa), and also the square and hexagon shapes record closed values for ellipse. The punch square shape record high tensile strain values (-0.0027), where punch adhering in sharp hole edges in return stroke. The auto desk inventor program is used to simulate analysis process of stress and strain (FEM) by using same values of forces in equations, the results were in same direction. This is refer to possibility of the simulate program in manufacturing factories to attain sustainable development for production.

ملخص البحث :

Abstract. The present study is to evaluate the performance of steel reinforcement under NaCl concentration chloride exposure. The loss of weight, yield stress and ultimate stress were tested to evaluate the performance of steel reinforcement before and after exposure. The exposure was also repeated under a variable temperature of (50, 60 and 70 C0 ). The steel was treated to improve its properties by using hardening in the oxy-acetylene torch, epoxy coating and aluminium spread coating. Results showed that the reduction in reinforcement properties was reduced significantly by using the hardening method and the maximum reduction in the performance of steel reinforcement was in the higher temperature chloride exposure. The increasing of concentration (0.1, 0.2, 0.3 and 0.4 NaCl %) was due to high corrosion in steel wire. The results showed that the treatment of reinforcement was significantly improved.

ملخص البحث :

The sudden stop of rotating shafts for any external and arbitrary reason due to develop of circumference distorsions because of dynamic angular displacement and by dividing on static angular displacement produce ratio called ( SSRSR ) to undesired elevations . The response according to