qq496257996
焊接类英语文章阅读Tapping the Low Hydrogen Porosity ProblemTapping the Low Hydrogen Porosity ProblemBy Dan Mahony, Technical Salesman, and Paul Gramp, Distributor Trainer, The Lincoln Electric Company.Stick Welding Porosity in a weld is considered poor quality. Porosity may, or may not, be visible to the naked eye. Occasionally porosity can be found in the face of the weld while sometimes the face may appear porosity free, but deep inside the weld, porosity may exist. Porosity looks "sponge like" or like tiny bubbles in the weld. Porosity in a weld can be located using several different methods of non-destructive testing, such as radiographic (x-ray), UT (ultrasonic) and die penetrate. "...strike the arc, then lift the electrode up for a moment or two, allowing a few drops of electrode to fall from the tip."Although some porosity found at the beginning of a weld made with low hydrogen electrodes is not always apparent, it is possible and the solution itself may be simple. Often, even with an experienced welder, weld testing will show slight porosity at the beginning of a weld for no apparent reason. Porosity is often found when using low-hydrogen electrodes such as E-7018, and it may be difficult to establish why this occurs.Stick Welding In order to understand the real cause, it is necessary to look at the way stick electrodes are manufactured, as well as how they are used in the field. The steel core wire, as we know, conducts electrical current from the electrode holder to the work . It also melts to become the filler metal. The chemical coating that forms the flux layer is extruded on to the steel core wire and baked in a controlled oven to remove moisture. The flux coatings major task is to vaporize and form a shielding gas to protect the weld puddle from nitrogen, hydrogen and oxygen.During manufacturing, after the coating is applied and it is still soft and pliable, a set of brushes removes coating to accommodate the electrode holder. Another set of brushes slightly tapers the work end of the electrode to expose the end of the steel core wire. This exposed end allows a short circuit to be established when it touches the work at the start of the weld. As the weld progresses, the steel wire burns slightly up inside the flux (approximately 1/8 of an inch), so the coating melts to form the necessary shielding gas. Striking a new electrode, however, the tapered coating at the end of the electrode provides only minimal shielding since some of the coating was intentionally removed to accommodate easier arc starting. Therefore, if the operator lowers the electrode into the puddle immediately, some porosity may result at the beginning of the weld, which is caused by insufficient amount of coating on the steel core wire.This condition also exists when re-striking an electrode that has already been used. Before striking an arc, the welder frequently taps the end of the electrode on the ground to break away flux at the tip. Breaking away the flux to expose the steel core wire, while helping to achieve the short circuit necessary to start the arc, creates conditions for improper arc shielding, sometimes resulting in porosity at the start of the weld. This practice is much more common with low hydrogen electrodes, since the core wire melts up inside the flux coating. Electrodes such as E-6010 and E-6011 use organic coatings (paper), which the coating tends to burn back enough to leave the end of the core wire exposed.Stick WeldingThis type of porosity can be avoided if the operator is trained to strike the arc correctly. Immediately after establishing the arc, lift the electrode up a short distance from the work and holding it there for a second or two, allow a few drops of molten steel to fall from the tip of the electrode. The arc will bring the tip of the electrode up to operating temperature quickly, enabling the core wire to burn up inside the flux coating and initiate the gassing effect of the flux. Then, when the electrode is lowered to the work, the weld will be properly shielded, and porosity will be minimized.Proper training is always important to achieving good results in welding. Training is even more critical when dealing with low hydrogen electrodes. A little understanding of how these electrodes differ and the consequences of improper electrode handling will pay big dividends in better weld quality and fewer porosity defects.参考资料：百度上搜焊接英语文章，有很多资源的
戴小卓269500767
有时候，离开熙熙攘攘的人群只是为了做更真的自己，为了获得那份完全属于自己的宁静。接下来，我给大家准备了 英语文摘 寻找属于自己的宁静,欢迎大家参考与借鉴。
英语文摘寻找属于自己的宁静
I’m an introvert—someone who prefers solitary[2] to social activities. Don’t misunderstand this as me being an awkward computer-nerd you see portrayed on televisions who can’t hold a decent conversation; instead, think of it as someone who simply needs to re-energize after spending the day in a crowd: like a battery with a low lifetime of sorts.[3]
1. extrovert: 性格外向者;introvert: 性格内向者。
2. solitary: 单独，独处。
3. 别误会，不要把我想象成你在电视上看到的那种笨拙的电脑呆子，连正常的对话都应付不来;相反，你可以想象我只是个待机时间短的电池，在人群中熙熙攘攘一天之后，需要恢复能量。awkward: 尴尬的，笨拙的;nerd: 书呆子;portray: 扮演，描绘;decent: 体面的，合适的。
My ideal day during the weekend would begin by getting nine hours of sleep and then lifting some weights in the morning after my breakfast has properly settled.[4] After a stress-relieving workout, I would get my post-workout meal in whilst watching a few episodes of Parks & Recreationto get some good laughs in.[5] Next would be to dance, nap, listen to music, stretch/yoga, walk my dog, or some activity to pass time that I enjoy doing at the time. After spending the majority of the day alone doing these activities I would then sit down in my room and play video games like League of Legends, or binge-watch on some anime that I’m currently obsessed with until I feel like it’s time to go to bed.”[6]
4. lift weights: 举重;settle: 解决。
5. stress-relieving: 减压的;whilst: 在……时;episode: (电视剧的)一集;Parks & Recreation:《公园与游憩》，美国一档情景喜剧;get in: 收获，获得。
6. League of Legends: 英雄联盟，一款游戏;binge-watch: 电视成瘾，此处指长时间观看;anime: 动漫。
Now if you asked me in person I would simply reply with, “Ummm… Workout, eat, watch TV, dance, and play video games.” My “energy gauge” charges up when I do hobbies by myself.[7] And in contrast, the needle goes towards “E” when I’m out and interacting with other people.[8] Coming up with awkward small talk, and interacting with most people is more of a nuisance[9] than fun.
7. energy gauge: 能量表，能量计;charge up: 充电，恢复能量。
8. 相反，我外出与他人社交时，仪表盘的指针就会向“E”转动。这里意在说明，社交互动耗费自己的能量。interact with: 与……互动。
9. nuisance: 令人讨厌的东西，麻烦事。
Now I wasn’t always an introvert. It used to be that making a person happy meant I had a great day. During high school I put myself into situations where I would have to interact with people for most of the day. I played team basketball and tennis; held positions in Associated Student Body and Key Club; stayed after school just to dick around with friends; and played CoD/Halo with friends.[10] All this was to limit the time I spent alone. I hated being alone, and it was probably because I was an only-child and never really had anyone to bond with when I got home. My personality at this time could be described as bubbly[11], overly-excited, weird, friendly, and easily outgoing. I loved being interacting with friends; it made me happy; it gave me energy. I’d even consider myself as an overall “people person[12]”.
10. hold position: 任职，担任;dick around: 瞎混，四处闲逛;CoD: Call of Duty: 使命召唤，一款游戏;Halo: 光晕，一款游戏。
11. bubbly: 活泼的，开朗的。
12. people person: 有人缘的人，受欢迎的人。
I ended high school on the highest note possible and hands down this was one of the proudest moments in my life for reasons that aren’t relevant.[13] Everything seemed like things were coming together and my hard work was finally paying off. I came to CMU with a good head on my shoulders and with brown, eager-fiery eyes that signified that I was ready to tackle anything that came my way.[14] Nothing would stop me from my future goals. And as freshman[15] year progressed I continued to balance the social and academic life pretty well.
13. end… on a high note: 圆满结束;hands down: 无疑地。
14. 来到卡内基梅隆大学时，我头脑聪明，满眼期待，我感觉我已经准备好应对即将面临的各种问题。eager-fiery: 热切而渴望的;tackle: 解决，处理。
15. freshman: 大一新生。
But by the end of freshman year I was unsatisfied with how I performed, they didn’t meet my own expectations[16]. Before, I met nearly every single goal I set forth[17] that I worked hard for and put my blood, sweat and tears in. But this time I didn’t. I’m sure most, at least my fellow CMU students, can relate seeing and reacting to any grade lower than a B for the first time during their post-secondary education[18]. It definitely wasn’t the greatest feeling in the world.
16. meet one’s expectation: 达到预期。
17. set forth: 提出，设定。
18. post-secondary education: 高等 教育 ，中学后教育。
So next year came and I worked even harder than before; consequently, the social aspect of my life started to become more of a pain to me. What really matters here is that I was cutting a substantial[19] part of my social life in order to do better in school. For the first time, being social was becoming a nag[20]. “Any type of socializing is a hindrance to my academic goals”, at least that’s what I had my brain playing on repeat when deciding to either spend Friday night studying or to go out and socialize.[21] I personally couldn’t find the formula to get perfect grades, a satisfying amount of sleep, and also live a social life that I used to know of.[22] It just wasn’t possible. If I wanted to do more of one thing, and sadly something had to be compromised[23] and so I chose to sacrifice the majority of social activities that I used to love doing.
19. substantial: 大量的，很多的。
20. nag: 困扰，烦扰。
21. hindrance: 妨碍，阻碍;play on repeat: (脑中)不停地想。
22. 就我而言，我找不到 方法 既能得到优秀的成绩、充足的睡眠，又得以继续我所熟悉的社交生活。formula: 方法。
23. compromised: 妥协的，让步的。
I returned home for the summer after sophomore[24] year which meant seeing my childhood friends. As soon as I got back I got invited to a small college party at the University of Washington, full of people I already knew during middle school as well as high school. But something was odd; something felt weird.[25] It’d been nearly a whole semester of not enjoying other people’s company and I was feeling this sort of anxiety of not excitement, but of discomfort or fear.
24. sophomore: 大学二年级学生。
25. odd: 古怪的，异常的;weird: 奇怪的，古怪的。
Now as we speak, I’m typing this up alone in my room with my dog right by my side and I’m totally okay with that. After certain events, I’ve come to not like strangers or engaging in small talk. If I had to choose, I’d choose to do things alone or with those rare friends where everything is just natural around them. If you think introverts don’t socialize at all, then you’re wrong. I simply don’t want be alone 100% of the time. Even people like us introverts need to be shown love and support.
Even after being in school for so long, why can’t I just turn on my extrovert switch back on[26]? I thought about this for a while and I still don’t really have an answer. But it’s not like being introverted makes me worse off[27] than being extroverted. So yeah, I’m happy to be introverted.
26. turn on switch back on: 重新打开(开关)，再次开始。
27. worse off: 恶化，每况愈下。
Being an extrovert has its pros and cons[28], as does being an introvert. I always hear negative things about introverts, and I don’t think these stigmas[29] apply to every single introvert out there. Silence is truly golden. So if you see one of us introverts just sitting there in silence don’t just go and panic and assume there’s something wrong.
I love silence. I need silence. If writing didn’t become such a chore[30] for the first 19 years of my life, I’m sure I would have enjoyed writing more than talking. I enjoy having a few close friends and spending quality time[31] with them. And by no means would I describe myself as shy.
28. pros and cons: 利弊，正反两面。
29. stigma: 污点，恶名。
30. chore: 困难的事，令人厌烦的事。
31. quality time: 高品质时间，有意义的时间 相关 文章 ：
1. 双语美文欣赏美
2. 经典双语散文欣赏生活的道路
3. 双语美文欣赏《 做你自己》
4. 美文欣赏《善待别人,善待自己》双语
5. 双语美文欣赏爱的力量
6. 8招改变生活的美丽秘诀(双语)
优质英语培训问答知识库
