Steel Authority of India

About: Steel Authority of India is a based out in . It is known for research contribution in the topics: Microstructure & Ultimate tensile strength. The organization has 797 authors who have published 661 publications receiving 9958 citations. The organization is also known as: SAIL.

Trailer articulation device

Abstract: An articulated trailer utilizing two pivot points and an angular transfer system to control the radial movement of the front axle during turning is disclosed. The articulated trailer comprises an elongated carriage having two spaced-part, wheeled axles. The rear axle rigidly attaches to the carriage while the front axle is pivotally mounted. The carriage front end comprises two spaced-apart pivot points, a hollow jack column assembly and a tongue assembly. A structural assembly supports the jack column assembly and the tongue assembly. A draw bar extends from the tongue assembly to the draft vehicle. Tie-rods attach the ends of the upper tongue assembly to a pair of plates. The plates are interconnected by a shaft. A responder plate is coupled to an electric motor. The electric motor selectively rotates to effect the radial movement of the tongue assembly to transfer angular movement to the jack column assembly. Therefore, the electric motor controls the radial movement of the front axle independently of the draft vehicle movement. Thus the direction of travel of the trailer can be selectively controlled. Limit devices control the angular movement of the jack column assembly and the tongue. When backing the trailer, a locking system may be deployed to prevent pivotal movement of the jack column assembly and the tongue assembly while permitting the unimpeded radial movement of the draw bar.

Heart rate and blood lactate in 400 m flat and 400 m hurdle running: a comparative study.

Abstract: This study was conducted on a group of male sprinters (n = 8) to compare heart rate (HR) and blood lactate (La) response in 400 m flat and 400 m hurdle running during weekly trial race. Durations of the flat and hurdle races were 51.65 +/- 1.51 and 58.27 +/- 1.97 sec respectively. Peak HR attained at the end of the flat and hurdle races were 192.4 +/- 5.3 and 193.6 +/- 4.1 beats/min, whereas, average HR during the events were 173.6 +/- 22.6 and 176.7 +/- 19.6 beats/min respectively. La level following the flat event (18.84 +/- 1.57 mmol/L) was found significantly (P < 0.05) higher than the post-hurdle race (16.14 +/- 1.97 mmol/L). The study indicates that cardiovascular stress is similar in both the events although flat race impose higher anaerobic glycolytic demand than hurdle run.

Enhancement of Microstructural and Mechanical Properties by Pulse Mode of Metal Transfer in Welded Modified Ferritic Stainless Steel

Abstract: The present study describes the enhancement of microstructural and mechanical properties by pulse mode of metal transfer in welded modified ferritic stainless steel (409 M) sheets (as received) of 4 mm thickness. The welded joints were prepared by varying modes of metal transfer at different heat input conditions (i.e. pulse mode at 0.5 kJ/mm and 0.9 kJ/mm and spray mode at 0.5 kJ/mm), using austenitic filler wire (i.e. 308 L) under Ar + 10% CO2 atmosphere. It has been observed that the pulse mode of metal transfer significantly alters the weld metal composition compare to spray mode which promotes comparatively stable austenite in the welds and also depicts significant enhancement in grain structure even with the higher heat input condition. Present study clearly shows that pulse mode enhances micro-hardness of welded joints and toughness values of weld metals compare to spray mode of metal transfer for a particular heat input.

Crack closure and fatigue crack growth rate in three point bend specimens of different widths

Abstract: — The crack closure stress intensity factor values and fatigue crack growth rates were determined in Three Point Single Edge Bend, SE(B), specimens prepared from rails manufactured using two different grades of rail steels. The width, and correspondingly the span, of the SE(B) specimens were varied eight fold; the thickness of all the specimens being the same. It is observed that the crack closure stress intensity factor values decrease with an increase in the width of SE(B) specimens. At a given value of ΔKeff, the fatigue crack growth rate (FCGR) is independent of the width. However, at a given value of ΔKeff, the FCGR is observed to decrease with increasing width. In view of the above results, the scope of application of the FCGR laws based on an effective stress intensity factor to the life prediction of components, requires careful examination.