Effect of Water Velocity on Erosion Corrosion Behavior

Effect of Water Velocity on Erosion Corrosion Behavior Effect of water velocity on erosion  corrosion behavior of materials used  in marine conditions Corrosion, among others, is one of the main and considerable causes which is liable for the failure of the equipment and the material used in marine applications. Up to now, the majority of the materials that have been developed for marine applications are carbon steel, copper-base alloys, nickel-base alloys, titanium and apparently stainless steel and its variations such as super austenitic, duplex and super duplex stainless steel. (Meng, 2009) Last decade, the use of composites in maritime industry has also increased. (Jones Summerscales, 2016) One parameter, which influences the extent of corrosion on these materials is the water flow velocity, as a result of mass transfer and other incidents, such as erosion corrosion. (Scheers, 1992) For that reason, they are required to withstand to a wide range of velocities. Water can be either static during shutdown periods or have movement. At low movement speed, the cathode reactants affect the rate of the erosion corrosion process. This most usually brings about higher rates of deterioration, but there are some cases in the case of passive alloys, that this results in decreased rates. Furthermore, the provision of oxygen on the external surface of the corroding metal is extremely dependent on the water velocity. (Chandler, 1985) Oxygen can fuel the cathodic reaction in seawater which can also lead to higher corrosion rates. In conditions where the water velocity is increased, apart from the corrosion arising from the electrochemical process of corrosion, there is also mechanical action with much worse consequences. In other words, high velocity results in enhanced erosion corrosion of the components and the installation parts. The concentration gradients in the bulk of the fluid are destroyed by the turbulent conditions. The action which affects neg atively the phenomenon of erosion corrosion appears in a very thin layer of the fluid which is bordering to the pipe wall. (Scheers, 1992) In addition to, there is also the impingement attack and cavitation corrosion which are more extreme forms of erosion corrosion. Conditions offering high water velocity can be found in tubes, pipes and rotating machinery. Figure 1:Schematic of turbulent eddy mechanism for downstream undercutting of erosion-corrosion pits On this dissertation, the effects of water velocity on erosion corrosion behavior of the materials that are used in marine conditions will be examined. Furthermore, the second part of this project will include the impingement of the water from different angles while the amount of the material loss during the impingement and electrochemical corrosion varies between different angles. Cathodic can be also applied, in order to investigate the effects on the erosion corrosion during the changes in flow velocity. It is very important and crucial to know exactly the effects of velocity because the combination of the electrochemical reactions with the synergy of the mechanical reactions due to the impingement in aqueous environments can cause horrible failures of the metallic components used in industry (Meng, 2009) . In addition there is also great need to know the difference in the number and in the size of the pits while velocity is increased (Wing, et al., 2016), as long as materials have suffered and caused serious accidents before in the marine environment and in the hole marine society. Moreover, pipes are used everywhere in ships and offshore structures, so after the study engineers will construct them with bigger safety and reliability (Jin, et al., 2016). The dissertation I about the experimental investigation of the consequences on erosion corrosion behavior in materials, as long as the impact of the impingement from different angles. Afterwards, an anode will be placed on the specimen to investigate with accuracy the changes on erosion corrosion. The major aim of this project is the accurate plot of the corrosion rates, in comparison with the different flow velocities. What is more, one of the aims of this research is the determination of the difference on corrosion behavior between materials and compare the deterioration process and extent of erosion to them. In other words, erosion corrosion, might not be the same in all marine materials, therefore engineers will have a better indication of the effect on each on of them, because in conditions where high velocity occurs, as the dissolved oxygen controls the rate of corrosion in sea water (Larson King, 1954) . It is still very difficult to choose the most optimum material for a specific job in the current working environment, selecting a more erosion corrosion resistant material. (Meng, 2009) The ongoing protocols for design and selection are extremely basic and are based on empirical service data (Neville Hu, 2001). Moreover, another aim is to compare the degree of electrochemical and mechanical reactions in changing angles. The durability of steels and cast iron and other materials will be further interpreted. Lastly, the removal of the protective oxide film in stainless steels might accelerate corrosion (Bonner, 2016) Many water characteristics influence the rate of corrosion process, like Ph, dissolved gases, temperature, dissolved salts, but the one under consideration is the flow velocity. The effect of velocity on corrosion is also Ph dependent. Seawater is alkaline and it is more at the base side 7.9-9.0 and carbonate ion concentrations increase as ph increases (Sabrowski Silva, 2010). Therefore, in basic or alkaline water, the higher velocities have as a consequence enhanced supply of the cathodic reactant, oxygen. For that reason, the cathodic reaction is stimulated and higher corrosion rates take place, causing erosive damage to the metal surface (Hodgkiess, 2013). According to (Meng, 2009), an increase on velocity has as a result the acceleration of corrosion on behalf of the motion of the fluid, as well as (Neville, et al., 1995) state that the reason of the increased rate of corrosion is the enhanced turbulence and the mixing of water on account of the supply of oxygen. Furthermore, as Giourntas stats in his study (Giourntas, et al., 2015), stainless steels have the ability to abide high flow rates. However, in the presence of solids I seawater the persistence is decreased. It also states the application of cathodic protection as a very important feature. As reported by (Neville, et al., 1999), with or without the absence of solids, the E corr drifts to more positive values, during the impingement. As stated by (Neville Hu, 2001), in places with high velocity and sudden changes in direction because of pimps, elbows in pipeworks etc. higher rates occur. Moreover, as Weber reports in (Webber, 1992) the effects are divided in three categories at low flow velocity, medium and high velocity. In the first category, natural convention is responsible, while at the second corrosion increases but without any significant mechanical effect of flow. During high velocities, the damage mechanisms becomes very complex. In keeping with (Li, et al., 1994), erosion corrosion problems enlarge catastrophically but the outflow of water. In agreement with Lin and Shao, with increasing impingement angles and velocities, the erosion is developing also. The rate of 1020 steel is lower than pure aluminums. During erosion conditions, many mechanisms act but only one or two of them is the principal mechanism. (Lin Shao, 1990) Concerning (Scheers, 1992), the simultaneous effects of velocity and ph have been investigated and turn out that in mild steel, there is an increase in corrosion rate with the velocity of flow, according to the ph value. Not to mention that, L. Wang notices that erosion corrosion increases rapidly with the development of the flow velocity at 14 m/s at 80% HR (Wang, et al., 2016). The dissertation of the effects of water velocity on erosion corrosion behavior of materials is mostly experimental. First of all, all available sources, papers and books will be investigated concerning erosion corrosion on materials that are used in marine condition. Furthermore, the effects of velocity and impingement angle will be searched. Relating the experiment, specimens have to be chosen. Possibly, only the major materials of maritime industry will be selected. These will have a cylindrical shape. Furthermore, those specimens will be placed in a recirculating rig as shown in the figure below. Afterwards, saline water will pass through a pump and therefore accelerate. Water will flow through pipes, where at the end of the piping system, a nozzle is installed, in order for the flow to take the exact preferable velocity. Nozzles will be changed. Directly vertical from the direction of the flow is the stagnation point. In the figure besides is a representation of the region where the liquid jet impinges to the solid material (Neville, 1995). The velocity depends on the diameter of the nozzle. Thence, water will impinge to the specimen causing erosive and corrosive damage. With the use of an equipment, the vertical impingement will change and erosive damage from different angles will be investigated. Afterwards, the exact amount of the material that has been degragated will be investigated through scale and metallography. References Bonner, R., 2016. Passivation coatings for micro-channel Coolers. s.l.:s.n. Chandler, K., 1985. Marine and offshore corrosion. s.l.:s.n. Giourntas, L. G., Hodgkiess, T. Galloway, A., 2015. Comparative study of erosion-corrosion performance on a range of stainless steels. s.l.:s.n. Hodgkiess, T., 2013. University of Strathclyde: General-Surface Corrosion. s.l.:s.n. Jin, H. ÃŽÂ ºÃƒÅ½Ã‚ ±ÃƒÅ½Ã‚ ¹ à Ã†â€™Ãƒ Ã¢â‚¬ ¦ÃƒÅ½Ã‚ ½., 2016. Failure analysis of multiphase flow corrosion-erosion with three-way injecting water pipe. s.l.:s.n. Jones, G. Summerscales, J., 2016. Marine applications of advanced fibre-reinforced composites. s.l.:s.n. Larson, T. King, R., 1954. Corrosion by Water at Low Flow Velocity. s.l.:s.n. Lin, F. Shao, H., 1990. Effect of impact velocity on slurry erosion and a new design of a slurry erosion tester. s.l.:s.n. Li, Y., Burstein, G. Hutchings, I., 1994. Influence of environmental composition and electrochemical potential on the slurry erosion-corrosion of aluminium. s.l.:s.n. Meng, H., 2009. Erosion-Corrosion of marine alloys. s.l.:s.n. Neville, A., 1995. An Investigation of the Corrosion Behaviour of a Range of Engineering Materials in Marine Environments. s.l.:s.n. Neville, A., Hodgkiess, T. Dallas, J., 1995. A study of the erosion-corrosion behaviour of engineering steels for marine pumping applications. s.l.:s.n. Neville, A. Hu, X., 2001. Mechanical and electrochemical interactions during liquid-solid impingement on high-alloy stainless steels. s.l.:s.n. Neville, A., Reyes, M., Hodgkiess, T. Gledhill, A., 1999. Mechanisms of wear on a Co-base alloy in liquid-solid slurries. s.l.:s.n. Sabrowski, A. Silva, P., 2010. ph:Regulation of Seawater, the role of Carbonae and Biicarbonate. s.l.:s.n. Scheers, P., 1992. The effects of flow velocity and pH on the corrosion rate of mild steel in a synthetic m;newater. s.l.:s.n. Scheers, P., 1992. The effects of flow velocity and pH on the corrosion rate of mild steel in a synthetic minewater. s.l.:s.n. Wang, L. ÃŽÂ ºÃƒÅ½Ã‚ ±ÃƒÅ½Ã‚ ¹ à Ã†â€™Ãƒ Ã¢â‚¬ ¦ÃƒÅ½Ã‚ ½., 2016. Erosionecorrosion behavior of 2205 duplex stainless steel in wet gas environments. s.l.:s.n. Webber, J., 1992. Br. Corrosion. s.l.:s.n. Wing, L. ÃŽÂ ºÃƒÅ½Ã‚ ±ÃƒÅ½Ã‚ ¹ à Ã†â€™Ãƒ Ã¢â‚¬ ¦ÃƒÅ½Ã‚ ½., 2016. Erosionecorrosion behavior of 2205 duplex stainless steel in wet gas environments. s.l.:s.n.

Man vs. Computer Essay

Since the beginning of time, man has thought up and brought to fruition countless inventions. Each has been more ingenious than the last. The human mind has created such brilliant things, but the computer may have been its greatest creation. It is ever changing, evolving and growing â€Å"smarter†. However, as the computer has evolved, mankind’s value may be threatened. The computer has already begun to overtake many of the vital functions that man has prided himself upon. While neither the mind nor the computer are perfectly productive on their own, they complement each other, and together create a more efficient way of living. Our lives are now dependent upon the computer and what it tells you. Even now as I type this journal entry on my computer, I am fully convinced that it will produce a result for me that is far superior to what I can manage using only my own two hands. It has been commonly said that the computer can never replace the human brain, because it was humans that created them. Is this a good reason why the computer must be inferior to humans? A computer has the ability to evaluate problems that humans can hardly even imagine, let alone approach. Even if a man can calculate the same problems as a computer, the computer can solve it much faster than the human mind. Maybe it is the subconscious attempt by us at reaching the next stage of evolution by our minds, creating a machine to do all the dirty work for us while we sit back and allows our brains to focus on creating, or destroying, as the case may be. The human brain has many flaws, yet it also has many an edge over the computer. It has the capacity to create, unlike the computer. It can work without full input, making logical assumptions about problems. A person can work with a wide variety of methods, seeing new and more efficient ways of handling problems. It can come up with infinite ways of getting around problems encountered in everyday life, while a computer has a limited selection of new tricks it can come up with, limited by its programming. Given the time, the human brain can learn to understand anything, and it can grasp the central theme of any concept. The computer tends to take all things in their entirety, which makes some problems near impossible to solve. Emotions are also an asset. Emotions have allowed the human brain to evolve beyond a problem-solving machine. Anger allows the imagination to roam, inventing concepts of new and more powerful weapons of destruction. Discontent induces the mind to conceive of new methods of fulfillment that could be expanded into something more. Puzzlement causes the mind to think of solutions. Curiosity leads to attempts to satisfy it, producing new discoveries and revelations. The human brain is as incredible as it is flawed, and the computer is a fantastic machine, but seriously lacking in many aspects. Perhaps the computer is not truly a competitor with the human brain, but rather it’s ideal. Don’t those who use the computer do so in order to supplement their own creative input? After all, the computer is far superior to the human brain in those aspects where the brain is weakest. Neither the mind nor the computer would be as good as the two of them are when they are working together.

Mixed Marriages

Relationships of every type are faced with a wide variety of problems and challenges in any given situation. Whether it involves our coworkers, neighbors, friends or family – the dynamics are relatively similar and predictable within a common cultural framework. These dynamics become more complex where marriage is concerned and differences in personalities come to the forefront. While these issues can be challenging enough for any married couple, there are additional difficulties specific to couples in a mixed marriage.For the purpose of this paper, mixed marriage is defined as a marriage of two people from different races, religions or cultures. Different customs and cultural backgrounds can directly impact your marriage and family life, as they tend to teach different values and priorities. This is particularly true in cases where a husband and wife were raised in different parts of the world. SPECIFIC POINTS Acceptance of the mix-marriage — is a major obstacle as oft en times the families of both partners do not approve of their marriage.Mixed-marriage couples deal with unique challenges compared to traditional couples. The challenge with interracial couples is respecting each other’s race and culture. If not, this can have a ripple effect to the extended family. Social attitude and prejudices For instance, one partner’s prevalent social attitudes and common prejudices may begin to show more openly one day. â€Å"When this happens, all you can do is to maintain a good-natured attitude and have lots of patience,† Hans adds. But potential obstacles need to be clearly identified and frankly addressed before moving ahead.Nationalistic, ethnic, or social pride can also drive a wedge between otherwise loving spouses. One partner may (subconsciously) feel superior because he or she grew up in a â€Å"higher† socio-economic class than the other. Or a spouse may feel owed something for having legalized the other’s citiz enship through matrimony. Pride also raises its head when one spouse believes that the other’s culture or beliefs are inferior or strange, thereby discounting the other person’s importance in the relationship.Racial offenses – You want to avoid making any remarks including those in a joking manner. You can also simply make this clear to those around you by telling them that you will avoid interactions with someone who continues to be negative regarding your marriage. Firmly tell the person you will not spend time with anyone who expresses racist views. Interracial couples sometimes experience rejection or stress from their own families. This may occur because of traditional beliefs that people should marry of the same cultural background.Regardless of whether this is an issue in your marriage, it's still important to remember to respect the beliefs and traditions of your partner's family. Interracial relationships are much more common today. However, they can st ill bring unique challenges. Along with being aware of these four areas but also having sensitive and open communication, an interracial marriage can overcome the additional challenges. Yet it also offers plenty of opportunities for couples to learn from each other and to gain new perspectives on their lives and marriage.Communication is a key issue — The nonverbal stimuli in a communication, like body language, can also lead to wrong expression and misunderstanding by different cultures. In addition, factor for space between people, certain actions, even a sense of taste needs to be taken to consideration. Communication of symbol is also important and can represent a group’s identity — speech like what’s up, and ‘yo’ are popular in Malaysia. Non verbal communication, High context and low context communication.Communication can be one of the biggest difficulties facing interracial or intercultural couples. This can include the challenge of li terally speaking different languages. At first, couples tend to enjoy hearing another language spoken, but this can also become a point of contention when misunderstandings occur or when the â€Å"foreign† language is spoken at family gatherings. Communication also becomes an issue when it affects the way a couple solves problems. Family Structure — issues such as male dominated societies (marriage culture), differing concepts of raising children.It always makes sense to find out as much as possible about your partner’s family but it makes special sense to do so in mixed marriages – especially concerning the culture and its traditional family structures. Mixed marriages often face additional struggles and challenges in the field of parenting. Raising a child always leads to conflicts if the parents are not on the same page. We weren’t sure how to raise our kid. Whose traditions do we pass on? † â€Å"My friends here do not struggle as much a s we do.But then again, they don’t have to synchronize two different sets of cultural and religious backgrounds,† Hans concedes. The involvement of extended family members in the child-rearing process, behavioral expectations, and the question of what is considered appropriate frequently cause heated discussions between Hans and Ruba. â€Å"Interestingly enough, we have always found a compromise so far. Despite our different outlooks, it helps us to know that we both want the best for our child.It’s not easy, but we have some common ground in that. For example, I agreed that Eman should be raised as a Muslim because her faith is very important to my wife. But I didn’t want her grandparents to have too much of a say. For me, child-rearing is the parents’ responsibility – and only theirs. † Different cultural attitudes towards the respective roles of men and women in the home can play havoc with this area of the relationship unless husba nds and wives can find ways to turn conflicts into opportunities for learning and growth.Religion and Politics — Partners in mixed marriages may be supportive of each other’s religious beliefs but still often run into unexpected issues. Differences in the way people in these marriages celebrate certain holidays or have dietary restrictions are to be expected. Politics can be problematic if world view is highly polarized – ie. Convervative/Liberal/Socialist/Communist Food Culture — We often clash over specific issues, like food. It drives me crazy that she doesn’t even let me cook pork. I think our arguments have gotten worse since the birth of our daughter.As in any relationship or marriage, both partners have to be flexible and open-minded when facing unexpected arguments and issues. INFORMATION TO DRAW FROM FOR SUMMARY OR WHATEVER In the first place, it’s important to acknowledge and understand how contrasting customs and cultural backgrou nds are likely to impact your marriage and family life. The way you’re brought up is the way you’ll live unless you make a conscious choice to embrace another option. Different customs and cultures teach different values and priorities.Normally, this means that interracial or multicultural couples have a unique need to bend, flex, compromise, and accommodate to one another’s contrasting ways of looking at life. This is especially true if a husband and wife grew up in different parts of the world. â€Å"In mixed marriages, arguments may come up more often because of the different cultural backgrounds,† Ruba says. â€Å"It’s just a lot more challenging. † Clashing values – When you come from different families of origin, you will make different assumptions about how a family works. These assumptions won’t always be compatible.However, this is the case in most marriages. In an interracial relationship, there’s a good chance that at least some of these challenges will be accented, especially if you choose to have children. Comparisons – You and your partner bring unique differences to the marriage. These differences should be embraced and may likely be some of the most enriching parts of your lives. You want to discuss with your partner what you each consider most important in any traditions or cultural beliefs. 1. You both come from ends of the world, where the way of life is totally different.Yours will be a major leap of adjustments. The difference in practices about religion as well as political beliefs may have to result to one acquiescing to the other’s belief just to have a harmonious relationship. 2. Prejudice on social practices, such as sex-selective abortion, often cause early breakup of the marriage as one may not be ready to fully embrace this new-found culture you are bound to live due to marriage. 3. The language barrier often results to miscommunication and misunderstandin g that sadly leads to divorce or separation.

IN THE STORY OF AN HOUR, MRS.MALLARD DIES VERY SUDEENLY AT THE END. IN THE YELLOW WALLPAPER. THE NARRATOR GOES INSANE. WHAT SIMILARITES OF CAUSE AND EFFECT Free Essay Example, 1000 words

Your Your Number 14 April 2006 Too Much Love: Similarities in â€Å"The Story of an Hour† and â€Å"The Yellow Wallpaper† When a marriage is a prison and the husband is a warden, strong women must eventually find a way to escape. Mrs. Mallard in â€Å"The Story of an Hour† by Kate Chopin and the narrator in â€Å"The Yellow Wall-Paper† by Charlotte Perkins Gilman are both intelligent Victorian women, but neither is allowed to publicly express herself. Instead, each woman is forced to keep her ideas bottled up inside because her husband smothers her with love and deprives her of her freedom. For the unnamed woman in â€Å"The Yellow Wallpaper, † this suffocation overcomes her and she escapes to the only place she can avoid John’s crushing caress: the madness of her own mind. Mrs. Mallard is allowed to finally release â€Å"the strongest impulse of her being† (Chopin 537) and when reality tries to replace the cork on her freedom, it is too much for her to bear. She dies of heartbreak. In these two stories, we see how the oppression of women under the guise of love leads to the destruction of both the love and the woman. Both characters are constrained in the very beginning by the social conventions of their time and class. We will write a custom essay sample on IN THE STORY OF AN HOUR, MRS.MALLARD DIES VERY SUDEENLY AT THE END. IN THE YELLOW WALLPAPER. THE NARRATOR GOES INSANE. WHAT SIMILARITES OF CAUSE AND EFFECT or any topic specifically for you Only $17.96 $11.86/pageorder now Many middle class women in that time period were expected to confine themselves to the home and domestic sphere, and even then, they were not expected to be in charge of the house, having lower class servants to do the cooking, cleaning and childrearing. It was thought that true women should not exert themselves, because they were too fragile to handle any strain. So it is for the characters in these stories. They are thought to be weak. Mrs. Mallard, we learn in the first sentence, â€Å"was afflicted with heart trouble† (Chopin 536) and thus â€Å"great care† (Chopin 536) is taken with her. Her family does not believe she can handle the news of her husband’s death on her own and does even allow her the luxury of sitting alone in her room. The narrator of â€Å"The Yellow Wallpaper† relates that her husband, John, â€Å"is very careful and loving† (Gilman 727) and John’s sister is â€Å"so careful of me† (Gilman 729). Further, her unnamed condition, which seems to be lack of stimulation, is exacerbated by a husband who belittles her with his every loving gesture. She says, â€Å"He laughs at me, of course, but one expect that in a marriage† (Gilman 725). He reduces her anger with him to a â€Å"nervous condition† (Gilman 726), dictates â€Å"a schedule prescription for each hour in the day† (Gilman 726), â€Å"hates to have [her] write a wordâ⠂¬  (Gilman 726), forbids her to have â€Å"stimulating people about† (Gilman 728), forces her to live in a nursery, and calls her â€Å"little girl† (Gilman 732).