...Metal forming is a general term, for a large group, that includes a wide variety of manufacturing processes. Metal forming processes are characteristic in that the metal being processed is plastically deformed in order to shape it into a desired geometry. In order to plastically deform a metal, a force must be applied that will exceed the yield strength of the material. The material actually gets stronger the more it is deformed plastically. This is called strain hardening or work hardening. Many metal forming processes are suitable for processing large quantities (i.e., bulk) of material, and their suitability depends not only upon the shape and size control of the product but also upon the surface finish produced. There are many different metal forming processes and some processes yield a better geometry and surface-finish than some others. Metal forming processes can be classified under two major groups. Bulk deformation processes and sheet metalworking processes. Bulk deformation is characteristic in that the work formed has a low surface area to volume ratio. In sheet metalworking the metal being processed will have a high surface area to volume ratio. Among the bulk Deformation, there are rolling, forging, extrusion and drawing method. Rolling is a metal forming process that deforms the work by the use of rolls. Rolling processes include flat rolling, shape rolling, ring rolling, thread rolling, gear rolling, and the production of seamless tube and pipe by rotary...
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...MCP 232 Lab Report Aim: To study the work hardening change in hardness in cold rolling operation Material: Low carbon steel Method of Test: 1. Rolling Treatment 2. Indentation Hardness test Observations: Rolling Treatment Least Count of micrometer= 0.001mm Specimen 1 Thickness= 2+ 48x0.001= 2.048mm S.No. | F1 (kN) | F2 (kN) | Total Force (kN) | 1. | 14 | 12.02 | 26.02 | 2. | 15.55 | 16.02 | 31.57 | * 5% reduction in each pass * Total thickness reduction= 10% Specimen 2 Thickness= 1.85mm S.No. | F1 (kN) | F2 (kN) | Total Force (kN) | 1. | 18.7 | 19.5 | 38.2 | 2. | 19.3 | 19.48 | 38.78 | 3. | 20.36 | 20.36 | 40.72 | * 5% reduction in each pass * Total thickness reduction= 15% Specimen 3 Thickness= 1.5+ 44x0.001= 1.544mm S.No. | F1 (kN) | F2 (kN) | Total Force (kN) | 1. | 20.9 | 20.6 | 41.5 | 2. | 20.8 | 20.64 | 41.44 | 3. | 20.04 | 20.33 | 40.37 | 4. | 21.7 | 21.96 | 43.66 | 5. | 21.03 | 20.34 | 41.37 | * 3% reduction in each pass * Total thickness reduction= 15% Specimen 4 Thickness= 1.4+0.006=1.406mm Indentation Hardness test Indentation Force=20N Specimen 1: I. 154HV II. 157HV III. 157HV Average Hardness= 157 HV Specimen 2: I. 162HV II. 160HV III. 159HV Average Hardness= 160.33 HV Specimen 1: I. 169HV II. 174HV III. 174HV Average Hardness= 172.33 HV Specimen 1: I. 184HV II. 183HV III. 181HV Average...
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...Grain size strengthening is a process that reduces the sizes of the grains in a material, typically by annealing. This works to increase the strength of the material through the fact that grain boundaries act as a barrier to dislocations. As can be seen in Figure 1, decrease in grain size causes an increase in proof stress. Cold working involves plastically deforming a material such that dislocations become concentrated. These dislocations then become entangled, hindering further dislocation movement, thereby increasing the strength of the material. As can be seen in Figure 1, proof stress can be increased dramatically by cold work hardening, but only to a point. (ii) Grain size strengthening and cold work hardening can be used together to form a much stronger material. Grain size strengthening reduces the size of grains whilst cold work hardening increases the grain size and decreases ductility. The combination of these two processes cancels the negative effects of each other. B1. Using the Hall-Petch equation: = Calculations: 193.06 ∴ = = 15 + − 15 − 1 + 193.06 110.32 ∴ Equating (1) and (2): 193.06 15 70 × 193.06 − − = = 70 + − 70 − 2 110.32 = 110.32 70 − =...
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...Cold Rolling Jeffry S. Asher DT1410 Unit 4 Assignment 2 ITT Technical Institute January 18, 2016 Cold rolling is a metal forming process in which the shape and the structure of steel are altered through drawing, extruding, hammering, pressing, rolling, spinning, and stretching at temperatures below the steel's recrystallization point, usually room temperature. These processes result in changes to the metal's composition which permanently increases its hardness and tensile strength, and improve the surface finish, but decrease ductility and impact resistance. After hot rolling, many steel products undergo a further processing in the cold state. This stage of processing may not necessarily alter the shape of the steel, but it does reduce its thickness and significantly improve its performance characteristics. Hot rolled coil is commonly known as cold rolled, also known as cold reduced. Cold rolling is a process by which the sheet metal or strip stock is introduced between rollers and then compressed and squeezed. The amount of strain introduced determines the hardness and other material properties of the finished product. The advantages of cold rolling are good dimensional accuracy and surface finish. Cold rolled sheet can be produced in various conditions such as skin-rolled, quarter hard, half hard, full hard depending on how much cold work has been performed. This cold working hardness is often called temper, although this has nothing to do with heat treatment temper...
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...Experiment 5 - Cold Work, Recovery, Recrystallization and Grain Growth Objective To study the effects of cold working on the microstructure and mechanical properties of 70/30 Cartridge Brass. Background A small percentage of the energy expended in plastically deforming a material remains stored in the metal as an increase in internal energy. Changes are produced in both its physical and mechanical properties. Principally, there is a marked increase in hardness and electrical resistivity with the amount of cold working. Microstructurally, this increment in internal energy is associated with an increase in the dislocation density as well as the density of point defects, such as vacancies and interstitials. For most metals, the dislocation density increases from the values of 106-107 lines/cm2 (typical of the annealed state) to 108-109 after a few percent deformation and up to 1011 -1012 lines/cm2 after heavy deformation. At a more macrostructural level, the grains become markedly elongated in the direction of working and heavily distorted. This distortion is evident from a bending of annealing twins and from unevenness in etching caused by local strain inhomogeneities. While the increased hardness and strength that result from the working operation can be important, it is often necessary to return the metal to its initial condition by annealing. This usually means holding the cold worked metal at a temperature above about 1/3 of the absolute melting point for a period of time. The...
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...Cold Working of Brass Kevin Louie MatE 25 October 20, 2014 | Marine Research Corporation | To: | Irene Huang | From: | Kevin Louie | Date: | September 29, 2014 | Re: | Determination on whether brass ingot can be used instead of plate form for a motor bracket application. | | | In response to the assigned investigation for Equipment used in the Oceanographic Research Platforms in the Arctic region, the following observation and test were performed. The scenario is having Research equipment installed on the Research Platforms that can survive harsh marine environments while operating for long periods of time with little or no maintenance. The material used for these equipment are to be made of brass plate because it is good corrosion resistance, easy machining tough. The question seeking for an answer of the investigation is “Can buying brass ingot and roll it flat to get a 60 percent reduction in thickness and hardness of 45 without it cracking?” For this experiment, there was two test that was conducted, Cold Working test and the Heat Treatment Test, on a sample of 260 Brass in ingot form. For the Cold Working Test, the first done was putting the sample through a Stanat Rolling Mill to reduce the thickness of the ingot. Part two of the Cold Working Test was to use the Rockwell Hardness Tester to measure the hardness of Brass. Do this test ten times at increments of -0.75 from 10.5mm to 3mm. At each targeted thickness, measure the width and length. The result...
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...Cold rolling is a process by which the sheet metal or strip stock is introduced between rollers and then compressed and squeezed. The amount of strain introduced determines the hardness and other material properties of the finished product. The advantages of cold rolling are good dimensional accuracy and surface finish. Cold rolled sheet can be produced in various conditions such as skin-rolled, quarter hard, half hard, full hard depending on how much cold work has been performed. This cold working (hardness) is often called temper, although this has nothing to do withheat treatment temper. In skin rolling, the metal is reduced by 0.5 to 1% and results in a surface that is smooth and the yield point phenomenon--excessive stretching and wrinkling in subsequent operations, is eliminated. This makes the metal more ductile for further forming and stretching operations. Quarter Hard, Half Hard, Full Hard stock have higher amounts of reduction, upto 50%. This increases the yield point; grain orientation and material properties assume different properties along the grain orientation. However, while the yield point increases, ductility decreases. Quarter Hard material can be bent (perpendicular to the direction of rolling) on itself without fracturing. Half hard material can be bent 90º; full hard can be bent 45º. Thus, these materials can be used for in applications involving great amounts of bending and deformation, without fracturing. Annealing, in metallurgy and materials...
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...¬¬¬Production of the Connecting Rod Drop Forged Connecting Rods Connecting rods are most commonly drop forged, firstly a blank steel bar with a rectangular or round cross section, it is heated to around 1300°C and is rolled to redistribute the masses to the larger and smaller ends. The most important part of the process takes place in a hammer unit, the steel rod is placed in a die and after a few consecutive blows of a hammer the steel bar is forced into the shape of the die, giving the connecting rod its shape. Drop forging produces flash around the edges of the connecting rod which is removed, the larger hole and sometimes the smaller hole (in larger connecting rods) are also simultaneously punched in this process. After the flash is removed the connecting rod is heat treated and then machined, the final stage of the process is the separation of the cap from the rod (unless the cap and the rod have been forged separately), this is usually done by sawing but an alternative is to use splitting. Alternative methods of production A newer technology called Sintering is becoming more popular to produce control rods; it begins with the sevrohydraulic pressing of powdered metal in its final alloy, to create a powdered preform of the control rod. Next the preform is heated to around 1120°C in an electrically heated furnace for around 15 minutes, the finished piece is now ready. The reason this technology has not taken the place of the drop forging process is because...
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...I designed a simple network, however, a simple network with the right security measures can become an extremely strong and defensive network. This base network design could be expanded upon to become a complex network. The first thing this network needs is a connection to the internet. Once the information leaves the internet it enters into a gateway. “A network gateway is an internetworking system capable of joining together two networks that use different base protocols” (Mitchell, “Gateway”). A gateway receives and sends data to and from the internet, and manipulates the information in a way so that the internal network can understand it. After the gateway is a Cisco ASA, ASA stands for Applied Security Appliance, “In brief, Cisco ASA is a security device that combines firewall, antivirus, intrusion...
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...Network Hardening Assignment 8 The Internet is vulnerable to myriads kinds of attacks, due to: 1. Vulnerabilities in the TCP-IP protocol 2. No global flow control mechanisms The above two problems lead to many TCP exploits and the dreaded DDoS attacks. We have devised a method of incrementally upgrading the network infrastructure at the transport level that solves the above problems and makes the network significantly more resilient to attacks, particularly the DDoS attack. The approach uses "hardened routers" -- routers that can do simple cryptographic functions (encryption, signatures) on all packets flowing int he network, as well as to participate in a hierarchical control network. We show how incremental deployment of such routers can make the Internet safer. Like all things dynamic, change is inevitable. Such is the case with your network environment. Upgrades and modifications to the network architecture can sometimes expose (or create) security holes. As such, it is important to consistently evaluate the Making a Business Case for Network Hardening Hardening a network does not always translate into spending large quantities of money. However, money will be required in some form or fashion. Whether that means spending it on new hardware, software, or man hours really depends on what needs to be addressed. It may include all of the above. The time may come when a cost/benefit analysis will be required by those in charge before hardening activities can move forward...
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...Network nodes are not directly aware that switches handle the traffic they send and receive, making switches the silent workhorse of a network. Other than offering an administrative interface, switches do not maintain layer three IP addresses, so hosts cannot send traffic to them directly. The primary attack against a switch is the ARP poisoning attack described earlier in the “Switches” section of this chapter. However, the possibility of an ARP attack doesn’t mean switches cannot be used as security control devices. As mentioned earlier, MAC addresses are unique for every network interface card, and switches can be configured to allow only specific MAC addresses to send traffic through a specific port on the switch. This function is known as port security, and it is useful where physical access over the network port cannot be relied upon, such as in public kiosks. With port security, a malicious individual cannot unplug the kiosk, plug in a laptop, and use the switch port, because the laptop MAC will not match the kiosk’s MAC and the switch would deny the traffic. While it is possible to spoof a MAC address, locking a port to a specific MAC creates a hurdle for a would-be intruder. Switches can also be used to create virtual local area networks (VLANs). VLANs are layer two broadcast domains, and they are used to further segment LANs. As described earlier, ARP broadcasts are sent between all hosts within the same VLAN. To communicate with a host that is not in your...
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...in researching 1) Developing a search strategy showed me how to organize my material and stay on topic. It also introduce me to key concepts which I have been using in my classes when studying and taking notes. Ironically I found using this method at work as well. Recently I found a solution to an ongoing network problem and my manager approached me asking me to fully research the resolution draft an email and send it out to the entire team.By using the search strategy I was able to gather the correct information that was needed to draft the email and send it to my team. 2)The Boolean operator AND OR NOT stuck in my head the most. I learned that this method is the main component to an effective statement and to broaden or narrow your search. When I use to search google without using the Boolean operator I always wondered why the search engine always gave me along list of searchs that didnt really relate to what I was looking up. By using this method I was able to get the exact results that I wanted and as I mention above this method was also used when I did my initial search statement for the email I sent to my colleagues on how to properly resolve the network issue. 3)Lastly the most important component of a research project is to cite the resources appropiately. In this course i was introduce to several styles of citing. There are different citing styles for different documentation styles. I had to go back and really study this method thoroughly as suggested by...
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...How would one counter an active attack? b) Give examples of two possible scenarios when one cannot be absolutely certain that an adversary is launching a modification-of-message attack or denial-of-service attack, even when the proper security protections are in place. Explain your answer. c) How could traffic analysis jeopardize security? Give an example to illustrate your answer. Question 2 (a) Is it likely to achieve perfect security for a network (i.e. to have a network that will never fail in terms of security) in the real business world? Give three possible reasons to substantiate your answer. (b) The computing speed is much faster these days compared to that some years back. On the other hand, old algorithms and systems are still in use. Give three reasons to explain this situation. Question 3 a) (i) Explain Security Services and Security Mechanisms. (ii) Suppose the main threat of a network is replay attack. Does the use of confidentiality services protect the network against such attack? Explain your answer. (iii) Is it always the case that only one mechanism can be used to achieve the provision of a particular service? Give an example to illustrate and explain the answer. (b) Explain how the following services ensure security of the systems or of data transfers and give possible example or scenario for each: i) Message authentication ii) Non- repudiation iii) Confidentiality ...
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...Case Study 1: Harriet’s Fruit and Chocolate Company Daniel Michovich Dr. Otto CIS532: Network Architecture and Analysis January 26, 2013 Mission Statement: Striving to be number one fruit and chocolate industry area wide. Introduction “Harriet’s Fruit and Chocolate Company was established in 1935 in the Pacific Northwest of the United States to ship gift baskets of locally grown peaches and pears to customers in the United States (Oppenheimer, 2011)” In regards to the physical infrastructure of Harriet’s Fruit and Chocolate Company, my investigation will reveal many important aspects to aid in the planning of the network design. First, I will determine the number of buildings to be used, as well as the distance between them and what equipment they will contain such as wiring closets or computer rooms and the current network devices. Determining the distance will help in the cabling design and wiring as well as the selection of technologies and devices to meet the design goals. My investigation will further reveal any architectural or environmental constraints, such as tall trees within the path that power lines may travel, that will assist in decisions such as whether wireless technologies are feasible as well as if there are any impediments to communications or installation, to include all hazards. Infrastructure architecture consists of the hardware, software, and telecommunications equipment that, when...
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...| | |The most damaging of the denial of service attacks can be a _______________ attacks, where an attacker uses zombie software distributed | |over several machines | | | | | |[pic] | |Bot | | | | | |[pic] | |Distributed denial of service ...
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