The Development of Maraging Steels Essay

Thermo-mechanically affected zone (TMAZ): In this region, the material has been plastically deformed by the friction stir welding tool, and the heat from the process will also have exerted some influence on the material. In the case of aluminium, it is possible to get significant plastic strain without recrystallization in this region, and there is generally a distinct boundary between the recrystallized zone and the deformed zones of the TMAZ. In the earlier classification, these two sub-zones were treated as distinct microstructural regions. However, subsequent work on other materials has shown that aluminium behaves in a different manner to most other materials, in that it can be extensively deformed at high temperature without recrystallization. In other materials, the distinct recrystallized region (the nugget) is absent, and the whole of the TMAZ appears to be recrystallized. This is certainly true of materials which have no thermally induced phase transformation which will in itself induce recrystallization without strain, for example pure titanium, b titanium alloys, austenitic stainless steels and copper. In materials such as ferritic steels and a-b titanium alloys (e.g.Ti-6Al-4V), understanding the microstructure is made more difficult by the thermally induced phase transformation, and this can also make the HAZ/TMAZ boundary difficult to identify

It has an excellent strength to weight ratio obtained from heat-treatment used in its formation. The heat treatment used for this steel does not use quenching rather uses air cooling or air

Overall, the 1018 and 1045 steel specimens displayed similar relationships between the heat-treating procedures. The 1045 steel had a greater tensile strength in all states except for the quenched state. In general, the 1018 steel specimens were more ductile than the 1045 steel specimens in all states.

Nickel is a prime advocate in Australia’s economy with it being one of the worlds largest producers, supplying around 13% of world production. Due to nickel’s distinctive properties, it creates primary alloys (almost 80% of nickel) that are tough, rust resistant, can withstand very high and low temperatures, and can be manipulated into any shape through its malleability/ ductility. Furthermore, nickel has countless other electrical, magnetic and heat resistant properties that are shown to be beneficial within the formation of these alloys. For example, almost 60% of nickel is used in the production of stainless, which is a combination of metals added to iron. Such metal alloys then go on to be used in construction, manufacturing of technology, electroplating, and even in batteries due to its electrical properties. Nickel is also a crucial nutrient in several chemical process’ inside the body, including iron absorption, averting blood conditions such as anaemia, and treating feeble bones.

Tungsten is applied to different metals for a variety of uses. In applications where strong steels are needed, tungsten can be added in higher and lower quantities based on need to increase strength due to its increased durability. Some common uses for the material are electron television tubes, filaments in electric lamps, winding/heating elements for electric furnaces, missile/ high temperature applications, and high speed tool steels to name a

Aluminium (AL) alloy 6061 is one of the most extensively used of the 6000 series aluminium alloys. Among the various useful aluminium alloys, aluminium alloy 6061 is typically characterized by properties such as fluidity, cast ability, corrosion resistance and high strength-weight ratio. Aluminium-based alloy MMCs has received increasing attention in recent decades as engineering applications. This alloy has been commonly used as a base metal for MMCs reinforced with a variety of fibres, particles and whiskers. Tungsten carbide (WC) is approximately two times stiffer than steel, with a Young's modulus of approximately 550GPa, and is much denser than steel or titanium.

This experiment demonstrated some key differences in material properties of several heat treatments for 4140 steel. Annealing creates a soft and ductile material that is easy to machine and perform other operations on. Quenching creates a very hard and brittle material that has extremely high yield and tensile strengths. Tempering quenched steel softens the steel and provides a tradeoff between the hard and strong quenched steel and the soft annealed steel. Engineers are benefited by an understanding of heat treatment because they are better able to predict how a material will perform when loaded if they know the heat treatment state of that material. Thus the results of this experiment, and others like it available in literature, are very

The use of steel rebars was started in construction in 18th century. Cast iron was used in the earlier age. Cast iron rebars were of high quality, and there was no corrosion. The technique was refined by embedding the steel bars in concrete. Square twisted steel bars (deformed bars) were introduced in 1960s but these were phased out due to their inherent inadequacies. Later the steel rebars of high yield strength were produced by raising carbon (>0.5 and <1.0 wt% content) as well as manganese contents. Carbon was added to steels in order to achieve strength and later on it was realized that higher content of carbon created problem of brittleness and accelerated rate of corrosion (due to the presence of higher proportion of cementite phases

Steel is an alloy primarily containing iron with slight amounts of carbon carefully controlled. Steel provided both the strength of cast iron and ductility of wrought-iron, making it a viable option for constructing tall buildings, particularly the construction of skyscapers.2 These two factors enabled steel to be molded into strong frames that did not require additional bracing for support, unlike iron. Therefore, steel made building light and tall structures a feasible idea. The primary type of steel favored for constructing tall structures were carbon steel. Carbon steel is a type of steel made from iron and a tiny amount of carbon (2% to be exact). Iron is quite soft in its pure form, yet by blasting it in a furnace, it becomes hard. However, this process results in the iron becoming more brittle at the same time due to the high content of carbon as well as other impurities. In order to make it less brittle, carbon is extracted from the iron until only a precise amount remains, creating steel. Iron is used because it is fairly strong despite being brittle after coming out of the furnace and is also very abundant. Carbon is used to make the iron stronger, and by controlling the amount of carbon in the iron, the iron becomes less brittle. Through this process, steel is

Alloys are used widely in our society for a number of purposes including in machinery and commercial products such as bowls made of stainless steel. A substance consisting of a mixture of two or more metals (or a metal with a non-metal) is defined as an alloy. The alloy which will be assessed in this ERT is High Tin Bronze. The composition of High Tin Bronze is of mainly copper (86%), tin (7.5%) and lead (0.3%) along with the other minor trace elements outlined in Table 1.0. High Tin Bronze is a wear-resistant, hard, strong alloy which is used for many (2). Being hard wearing and corrosion resistant, high tin bronze is used mainly for valves and plumbing, water appliances, pump components and gears (3).

The specific heat capacity of steel was calculated and produced a value of JKg.°C .

• Size and weight of the product is not a back drop for the casting process

This can be confirmed by comparing data from the experiment to accepted data for non-treated AISI 1018 steel. During the experiment, two metal specimens were tested on the hardness testing machine, using the HRB scale. From these values the hardness and tensile strength of the specimens can be calculated and compared. After this, the two specimens were put through a polishing process. This process leaves the specimens with a mirror like finish. A 2% Nital solution, a combination of nitric acid and methanol, is then put on the polished faces. The specimens are then ready to be viewed under the microscope where the grain structures can be observed. The treatment these metals have experienced should affect certain properties of their microstructure. It is expected that the fully annealed specimen will be softer than the untreated specimen because larger grains are produced in the annealing process, unlike that of the cold-worked specimen. This specimen will be harder and have a higher strength than the untreated specimen because the cold-working makes the grains smaller and more compact. There may be some error associated with the results obtained in this experiment due to imperfections in material handling and flaws in the specimens, but it is expected that this experiment accurately illustrates how the treatment process affects the properties of metals.

Thermodynamics can be used to explain corrosion in such a way that almost all metals and alloys, which are produced from their ores by applying external energy, are in fact in an unstable thermodynamic state. Ores have a low energy states that are the stable states. Therefore from thermodynamics point of view, metals and alloys will have a tendency to return to their stable energy state through reacting with corrosive environments. In fact, corrosion products usually have a composition similar to their original ores, therefore corrosion is a reverse process of extractive metallurgy, and figure (1) illustrates this concept [4].

There are many different forms of steel alloys used today. They are tailored during their processing phases to meet the wide array of engineering applications. Steel alloy in its simplest form is a basic mixture of Iron and Carbon and by varying the carbon content, the rate of cooling and the addition of impurities like Chromium for high corrosion resistance, we are able to derive alloys of different mechanical properties such as stainless steel and tool steels as these 3 factors affect the microstructure of the steel. This can be understood by the simple phase diagram of Iron and Carbon in Figure 1.1.