An Investigation into the Development of Prospective Indian Austenitic Stainless Steels

The development of substitute stainless steels in which all or the bulk of nickel in the standard austenitic stainless grades is replaced by manganese became it live issue in many steel -producing countries during world War 11 due to restricted or nonavailability of nickel . The research and development work carried out during the war period yielded a series of commercially useful alloy steels, which are enumerated. The paper goes on to refer to an investigation in progress in the National Metallurgical Laboratory into the development of substitute austenitic stainless steels based on the use of manganese, nitrogen , copper, chromium and rare earth additions.The results of experi-mental heats made are presented in terms of working prop-erties , metallographic studies, corrosion resistance under different media, interoranular brittleness and physical tests, etc. Tentative views are expressed on the merits of these austenitic stainless compositions under Indian conditions , which will be reviewed after further work which is being pursued in the National 'Metall-urgical Laboratory along lines stated

Manufacture in India of Ferro Alloys used in Alloy Steel Industry

The paper starts with an outline of established methods of manufacture of different ferro-alloys required for making alloy steels with a comparison of their merits as judged by the products made. The ferro-alloys discussed include those based on manganese, chromium, silicon, tungsten, vanadium and phosphorus and of different qual-ities and grades. The position of the production of the individual ferro-alloys in India is discussed and the great importance emphasized of expanding production of those required in relation to the expansion of the Indian iron and steel industry. A programme of ferro- alloy production is outlined, with discussion of availability of raw materials, manufacturing capacity and economic factors

Tempering of Die-steels based on indigenous materials

This paper present studies on the effects of quenching temperature, tempering temperature and time on the hardness of three die steels of similar carbon contents but having increasing chromium percentages. While tempering in the range of 150°C to 400°C it was observed that hardness decreased as quenching temperature was raised. All the steels showed secondary hardening phenomenon in relation to the variables mentioned above. It was also observed that on tempering the steels above 450°C, after prior quenching from increasing temperatures, hardness gradually increased upto the quenching temperature of 1100°C, beyond which followed a decrease in hardness. This phenomenon was the decrease in hardness. This phenomenon was the same at all tempering temperatures upto 601°C, but the increase in hardness from low quenching temperatures to the maximum quenching temperature was less at 450°C than at the higher temperatures and attained a maximum at 600°C secondary hardening decreased with the increase of quenching temperatur

The Effect of Misch Metal Additions on the Structure and Workability of Al-Mg (7-100/.) Alloys

ON the alloying elements used in aluminium alloys, copper was one of' the earliest employed commercially and for many years it has been the principal one. Aluminium-copper alloys to which manganese, magnesium or silicon has been added, belong to the important group generally known as "Duralumin". The binary alloys of aluminium with magnesium attra- cted the interest of investigators as early as 1900. There have been numerous attempts to utilise for general purposes alloys containing as Much as 10% magnesium ; alloys containing up to 30% magnesium have been used for special purposes

Development of low tungsten substitute tool steels

Tunsten is a very important alloying element in high speed tool steel, hot and cold work die steel and permanent magnet alloys, but its ore deposits are limited to a few countries. Continuous development user the years to reduce tungsten content in convent- ional 18-4-1 high speed steel i.e. 18% tungsten, 1% chromium and 1% vanadium, has led to increase of molybdenum, cobalt, chromium or vanadium. These steels have a hyper eutectoid structure in the fully hardened state in which complex carbides are embedded in martensite matrix. Both of these constituents in high speed steel retain higher hardness at high temperature than their counterpart in plain carbon steel. Many such high speed steels with low amount or without tungsten have been developed. These low tung- sten steels' apart from replacing the non-available alloying elements have the additional advantage of requiring lower hardening temperature than high speed tool steel containing 18% tungsten, thus avoiding the formation of coarse grain size in steel

Hot Dip Aluminising of Steel Wire- Laboratory Scale Investigations and Pilot Plant Studies

Protective quality of aluminium due to its adherent surface oxide film is well known. In hot-dip aluminising the use is made of this protective nature of aluminium by coating the steel base by dipping it in molten aluminium bath there-by getting an outer aluminium layer & an iron-aluminium layer at the interface. The interfacial alloy layer though possessing good atmospheric corrosion and resistance to oxidation at high temperature is brittle in nature and such must be kept to a minimum of thickness where the end use of aluminised product is for deep drawing, forming etc. Hot-dip aluminium coating on steel base comprising the outer aluminium layer and an alloy layer in the interface should possess both atmospheric & high temperature corrosion resistance

Study of microstructure of chill cast aluminium bronzes (Cu-AI-Fe-Mn)

SUBSTANTIAL information is available on the microstru-ctures of high tensile aluminium -bronzes but most of the literature is pertaining to the alloys containing nickel. Exhaustive amount of work was carried out by Gupta et al. at the National Metallurgical Laboratory to study the mechanical properties of aluminium-bronze alloys in the chill-cast condition without nickel addition, the results of which have already been reported in an earlier paper. The present paper relates to the study of microstructures of these chill-cast aluminium-bronze alloys. A few microstructures of Cu-Al-Fe system have been given by Copper Development Association in their recent publication on aluminium-bronzes.

Study of Microstructure of Chill Cast Aluminium Bronzes (Cu-Al-Fe-Mn)

Substantial information is available on the microstr-uctures of high tensile aluminium bronzes but most of the literature is pertaining to the alloys containing nickel. In the present paper authors have studies and presented the microstructures of various nickel-free aluminium bronze alloys containing iron and manganese. As an exhau-stive amount of work had been done at National Metall-urgical Laboratory to study the mechanical properties of such aluminium bronze alloys in the chill cast condition, the present microstructure study is also limited to the as cast alloys

Medical research and ethics - Revisited

Ethics in the medical research is known since many years; however, there have been new developments in this area recently. A phenomenal improvement in the health-care system, leading to increased life expectancy, and thereby, newer lifestyle and other health-related diseases has opened avenues for newer drugs and health-care technology. However, these have to be tried and tested in the context of the disease epidemiology, health-care delivery and of course, medical ethics. Monitoring and evaluation of the treatment regimes of well documented effective medicines is also required. This is the core of medical research. With the ever increasing concept of evidence-based medical system, and thereby, a rapid rise in the number of clinical trials; the role of medical ethics is potentially increasing to keep the patient

Substitution of galvanising by aluminising of steels

ALUMINISING has been accepted by the Government of India as it substitute for galvanising because of the existing scarcity of zinc. Zinc resources of our country are limited whereas minerals for extraction of aluminium are available in plenty. The Hindustan Steel (P ) Ltd., has decided to have provision for strip aluminising plant at Rourkela and Tata Iron and Steel Co. Ltd., may also be going for strip alum-inising adopting the Sendzimir Process . Bokaro Steel Plant has also made provision for aluminising of steel strip