2016年4月25日星期一
2016年4月12日星期二
US trade deficit expands to $47.1 billion in February
The US Census Bureau and the US Bureau of Economic Analysis, through the Department of Commerce, announced today that the goods and services deficit was $47.1 billion in February, up $1.2 billion from $45.9 billion in January, revised. February exports were $178.1 billion, $1.8 billion more than January exports. February imports were $225.1 billion, $3.0 billion more than January imports.
The February increase in the goods and services deficit reflected an increase in the goods deficit of $0.9 billion to $64.7 billion and a decrease in the services surplus of $0.3 billion to $17.7 billion. Hope SEKO Machinery Company's tube mills exports will increase in the future.
Year-to-date, the goods and services deficit increased $10.8 billion, or 13.1 percent, from the same period in 2015. Exports decreased $20.5 billion or 5.5 percent. Imports decreased $9.7 billion or 2.1 percent.
The February figures show surpluses, in billions of dollars, with South and Central America ($2.7), OPEC ($1.9), Saudi Arabia ($1.3), and Brazil ($0.4).
Deficits were recorded, in billions of dollars, with China ($32.1), European Union ($10.6), Japan ($5.4), Germany ($5.2), Mexico ($5.1), South Korea ($2.8), India ($2.4), Italy ($2.4), France ($1.5), Canada ($1.0), and United Kingdom ($0.5).
The deficit with China increased $1.0 billion to $32.1 billion in February. Exports decreased $0.3 billion to $8.4 billion and imports increased $0.8 billion to $40.5 billion. （From SteelOrbis）
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Suggested Reading: What are the Wootz steel and Damascus steel (2)?
US-NAFTA freight falls 7.2 percent in 2015
All five major transportation modes – truck, rail, pipeline, vessel and air – carried less US freight with North American Free Trade Agreement (NAFTA) partners Canada and Mexico by value in 2015 than in 2014. The total value of cross-border freight carried on all modes fell 7.2 percent from 2014 to $1.1 trillion in current dollars, according to the US Department of Transportation’s Bureau of Transportation Statistics (BTS). The price of the SEKO Machinery’s Welded Pipe Making Machine also fell. The value of commodities moving by truck declined 0.4 percent, the smallest decrease from 2014 to 2015 of any mode, 0.4 percent. The value of freight on other modes also declined: air 1.8 percent; rail 7.1 percent; vessel 29.7 percent; and pipeline 39.4 percent. A drop in the price of crude oil in 2015 played a key role in the large declines in the dollar value of goods shipped by vessel and pipeline. Average monthly prices for crude petroleum and refined fuel are available from the US Energy Information Administration. The 7.2 percent decline in the value cross-border freight from 2014 to 2015 was almost entirely due to the decline in crude oil and petroleum prices. The value of petroleum-related commodity shipments declined almost 40 percent year-over-year while the value of other freight dropped 0.9 percent. In 2015, petroleum-related commodities comprised 10.8 percent of the total value of US North American freight, down from 16.6 percent in 2014. Some data used to calculate the percentages in this paragraph comes from US International Trade Commission Interactive Tariff and Trade Data, which allows the separation of petroleum and non-petroleum components of mineral fuels. Trucks carried 64.3 percent of US-NAFTA freight, a 2.2 percentage point increase from 2005, and continued to be the most heavily utilized mode for moving goods to and from both US-NAFTA partners. Trucks accounted for $359.8 billion of the $589.9 billion of imports (61.0 percent) and for $351.9 billion of the $516.4 billion of exports (68.2 percent). Rail remained the second largest mode, moving 14.9 percent of all US-NAFTA freight, followed by vessel, 6.6 percent; pipeline, 5.2 percent and air, 3.9 percent. The surface transportation modes of truck, rail and pipeline carried 84.4 percent of the total value of US-NAFTA freight flows. (by SteelOrbis)
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Suggested Reading: Steel production Technology
Material properties of the steel
To inhibit corrosion, at least 11% chromium is added to steel so that a hard oxide forms on the metal surface; this is known as stainless steel. Tungsten interferes with the formation of cementite, allowing martensite to preferentially form at slower quench rates, resulting in high speed steel. On the other hand, sulfur, nitrogen, and phosphorus make steel more brittle, so these commonly found elements must be removed from the steel melt during processing.
Iron is commonly found in the Earth's crust in the form of an ore, usually an iron oxide, such as magnetite, hematite etc. Iron is extracted from iron ore by removing the oxygen through combination with a preferred chemical partner such as carbon that is lost to the atmosphere as carbon dioxide. This process, known as smelting, was first applied to metals with lower melting points, such as tin, which melts at approximately 250 °C (482 °F) and copper, which melts at approximately 1,100 °C (2,010 °F). In comparison, cast iron melts at approximately 1,375 °C (2,507 °F).[3] Small quantities of iron were smelted in ancient times, in the solid state, by heating the ore buried in a charcoal fire and welding the metal together with a hammer, squeezing out the impurities. With care, the carbon content could be controlled by moving it around in the fire.
All of these temperatures could be reached with ancient methods that have been used since the Bronze Age. Since the oxidation rate of iron increases rapidly beyond 800 °C (1,470 °F), it is important that smelting take place in a low-oxygen environment. Unlike copper and tin, liquid or solid iron dissolves carbon quite readily. Smelting, using carbon to reduce iron oxides, results in an alloy (pig iron) that retains too much carbon to be called steel. Welded steel tube mill andwelded steel pipe, please choose to SEKO Machinery Company to buy. The excess carbon and other impurities are removed in a subsequent step.
Other materials are often added to the iron/carbon mixture to produce steel with desired properties. Nickel and manganese in steel add to its tensile strength and make the austenite form of the iron-carbon solution more stable, chromium increases hardness and melting temperature, and vanadium also increases hardness while making it less prone to metal fatigue.
The density of steel varies based on the alloying constituents but usually ranges between 7,750 and 8,050 kg/m3 (484 and 503 lb/cu ft), or 7.75 and 8.05 g/cm3 (4.48 and 4.65 oz/cu in).
Even in a narrow range of concentrations of mixtures of carbon and iron that make a steel, a number of different metallurgical structures, with very different properties can form. Understanding such properties is essential to making quality steel. At room temperature, the most stable form of pure iron is the body-centered cubic (BCC) structure called ferrite or α-iron. It is a fairly soft metal that can dissolve only a small concentration of carbon, no more than 0.005% at 0 °C (32 °F) and 0.021 wt% at 723 °C (1,333 °F). At 910 °C pure iron transforms into a face-centered cubic (FCC) structure, called austenite or γ-iron. The FCC structure of austenite can dissolve considerably more carbon, as much as 2.1% (38 times that of ferrite) carbon at 1,148 °C (2,098 °F), which reflects the upper carbon content of steel, beyond which is cast iron.
When steels with less than 0.8% carbon (known as a hypoeutectoid steel), are cooled, the austenitic phase (FCC) of the mixture attempts to revert to the ferrite phase (BCC). SEKO Machinery Company's Austenitic stainless steel tube mill is environmental protection and energy saving, quality is very good. The carbon no longer fits within the FCC structure, resulting in an excess of carbon. One way for carbon to leave the austenite is for it to precipitate out of solution as cementite, leaving behind a surrounding phase of BCC iron that is low enough in carbon to take the form of ferrite, resulting in a ferrite matrix with cementite inclusions. Cementite is a hard and brittle intermetallic compound with the chemical formula of Fe3C. At the eutectoid, 0.8% carbon, the cooled structure takes the form of pearlite, named for its resemblance to mother of pearl. On a larger scale, it appears as a lamellar structure of ferrite and cementite. For steels that have more than 0.8% carbon, the cooled structure takes the form of pearlite and cementite.
Perhaps the most important polymorphic form of steel is martensite, a metastable phase that is significantly stronger than other steel phases. When the steel is in an austenitic phase and then quenched rapidly, it forms into martensite, as the atoms "freeze" in place when the cell structure changes from FCC to a distorted form of BCC as the atoms do not have time enough to migrate and form the cementite compound. Depending on the carbon content, the martensitic phase takes different forms. Below approximately 0.2% carbon, it takes on a ferrite BCC crystal form, but at higher carbon content it takes a body-centered tetragonal (BCT) structure. There is no thermal activation energy for the transformation from austenite to martensite. Moreover, there is no compositional change so the atoms generally retain their same neighbors.
Martensite has a lower density than does austenite, so that the transformation between them results in a change of volume. In this case, expansion occurs. Internal stresses from this expansion generally take the form of compression on the crystals of martensite and tension on the remaining ferrite, with a fair amount of shear on both constituents. If quenching is done improperly, the internal stresses can cause a part to shatter as it cools. At the very least, they cause internal work hardening and other microscopic imperfections. It is common for quench cracks to form when steel is water quenched, although they may not always be visible.
There are many types of heat treating processes available to steel. The most common are annealing, quenching, and tempering. Heat treatment is effective on hypereutectoid steel. Hypoeutectoid steel does not harden from heat treatment. Annealing is the process of heating the steel to a sufficiently high temperature to soften it. This process goes through three phases: recovery, recrystallization, and grain growth. The temperature required to anneal steel depends on the type of annealing to be achieved and the constituents of the alloy. Annealing equipment to choose SEKO Machinery.
Quenching and tempering first involves heating the steel to the austenite phase then quenching it in water or oil. This rapid cooling results in a hard but brittle martensitic structure. The steel is then tempered, which is just a specialized type of annealing, to reduce brittleness. In this application the annealing (tempering) process transforms some of the martensite into cementite, or spheroidite and hence reduces the internal stresses and defects. The result is a more ductile and fracture-resistant steel.
Email: sevvice@gdseko.com
Skype:Lucy Xie,SEKO Machinery
Suggested Reading: US-NAFTA freight falls 7.2 percent in 2015
How to make steel in ancient times?
Steel was known in antiquity, and possibly was produced by managing bloomeries and crucibles, or iron-smelting facilities, in which they contained carbon. Carbon steel welded pipe making machine's quality is very good, price is cheap, welcome to SEKO Machinery choose and buy!
The earliest known production of steel are pieces of ironware excavated from an archaeological site in Anatolia (Kaman-Kalehoyuk) and are nearly 4,000 years old, dating from 1800 BC. Horace identifies steel weapons like the falcata in the Iberian Peninsula, while Noric steel was used by the Roman military.
The reputation of Seric iron of South India (wootz steel) amongst the Greeks, Romans, Egyptians, East Africans, Chinese and the Middle East grew considerably. South Indian and Mediterranean sources including Alexander the Great (3rd c. BC) recount the presentation and export to the Greeks of 100 talents of such steel. Metal production sites in Sri Lanka employed wind furnaces driven by the monsoon winds, capable of producing high-carbon steel. Large-scale Wootz steel production in Tamilakam using crucibles and carbon sources such as the plant Avāram occurred by the sixth century BC, the pioneering precursor to modern steel production and metallurgy.
Steel was produced in large quantities in Sparta around 650 BC.
The Chinese of the Warring States period (403–221 BC) had quench-hardened steel, while Chinese of the Han dynasty (202 BC – 220 AD) created steel by melting together wrought iron with cast iron, gaining an ultimate product of a carbon-intermediate steel by the 1st century AD.[24][25] The Haya people of East Africa invented a type of furnace they used to make carbon steel at 1,802 °C (3,276 °F) nearly 2,000 years ago. East African steel has been suggested by Richard Hooker to date back to 1400 BC.
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Skype:Lucy Xie,SEKO Machinery
Suggested Reading: Material properties of the steel (3)
What are the Wootz steel and Damascus steel ?
Evidence of the earliest production of high carbon steel in the Indian Subcontinent are found in Kodumanal in Tamil Nadu area, Golconda in Andhra Pradesh area and Karnataka, and in Samanalawewa areas of Sri Lanka. This came to be known as Wootz steel, produced in South India by about sixth century BC and exported globally. The steel technology existed prior to 326 BC in the region as they are mentioned in literature of Sangam Tamil, Arabic and Latin as the finest steel in the world exported to the Romans, Egyptian, Chinese and Arabs worlds at that time – what they called Seric Iron. A 200 BC Tamil trade guild in Tissamaharama, in the South East of Sri Lanka, brought with them some of the oldest iron and steel artefacts and production processes to the island from the classical period. The Wootz steel belongs to special steel products, if you want to buy the special steel pipe welding machine, the best choice is SEKO Machinery Company! The Chinese and locals in Anuradhapura, Sri Lanka had also adopted the production methods of creating Wootz steel from the Chera Dynasty Tamils of South India by the 5th century AD. In Sri Lanka, this early steel-making method employed a unique wind furnace, driven by the monsoon winds, capable of producing high-carbon steel. Since the technology was acquired from the Tamilians from South India, the origin of steel technology in India can be conservatively estimated at 400–500 BC.
Wootz, also known as Damascus steel, is famous for its durability and ability to hold an edge. It was originally created from a number of different materials including various trace elements, apparently ultimately from the writings of Zosimos of Panopolis. However, the steel was an old technology in India when King Porus presented a steel sword to the Emperor Alexander in 326 BC. It was essentially a complicated alloy with iron as its main component. Recent studies have suggested that carbon nanotubes were included in its structure, which might explain some of its legendary qualities, though given the technology of that time, such qualities were produced by chance rather than by design. Natural wind was used where the soil containing iron was heated by the use of wood. The ancient Sinhalese managed to extract a ton of steel for every 2 tons of soil, a remarkable feat at the time. One such furnace was found in Samanalawewa and archaeologists were able to produce steel as the ancients did.
Crucible steel, formed by slowly heating and cooling pure iron and carbon (typically in the form of charcoal) in a crucible, was produced in Merv by the 9th to 10th century AD. In the 11th century, there is evidence of the production of steel in Song China using two techniques: a "berganesque" method that produced inferior, inhomogeneous, steel, and a precursor to the modern Bessemer process that used partial decarbonization via repeated forging under a cold blast.
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Skype:Lucy Xie,SEKO Machinery
Suggested Reading: How to make steel in ancient times?
Modern steelmaking process
Since the 17th century the first step in European steel production has been the smelting of iron ore into pig iron in a blast furnace. Originally employing charcoal, modern methods use coke, which has proven more economical.
Processes starting from bar iron
In these processes pig iron was "fined" in a finery forge to produce bar iron, which was then used in steel-making. Thesteel pipe welding machine from SEKO Machinery Company is your best choice!
The production of steel by the cementation process was described in a treatise published in Prague in 1574 and was in use in Nuremberg from 1601. A similar process for case hardening armour and files was described in a book published in Naples in 1589. The process was introduced to England in about 1614 and used to produce such steel by Sir Basil Brooke at Coalbrookdale during the 1610s.
The raw material for this process were bars of iron. During the 17th century it was realized that the best steel came from oregrounds iron of a region north of Stockholm, Sweden. This was still the usual raw material source in the 19th century, almost as long as the process was used.
Crucible steel is steel that has been melted in a crucible rather than having been forged, with the result that it is more homogeneous. Most previous furnaces could not reach high enough temperatures to melt the steel. The early modern crucible steel industry resulted from the invention of Benjamin Huntsman in the 1740s. Blister steel (made as above) was melted in a crucible or in a furnace, and cast (usually) into ingots.
Processes starting from pig iron
The modern era in steelmaking began with the introduction of Henry Bessemer's Bessemer process in 1855, the raw material for which was pig iron. His method let him produce steel in large quantities cheaply, thus mild steel came to be used for most purposes for which wrought iron was formerly used. The Gilchrist-Thomas process (or basic Bessemer process) was an improvement to the Bessemer process, made by lining the converter with a basic material to remove phosphorus. If you want to buy the iron pipe welding machine, please choose SEKO Machinery Company, welcome to inquire, email:sevvice@gdseko.com .
Another 19th-century steelmaking process was the Siemens-Martin process, which complemented the Bessemer process. It consisted of co-melting bar iron (or steel scrap) with pig iron. SEKO Machinery’s tube mill has cheap price and high quality.
These methods of steel production were rendered obsolete by the Linz-Donawitz process of basic oxygen steelmaking (BOS), developed in the 1950s, and other oxygen steel making methods. Basic oxygen steelmaking is superior to previous steelmaking methods because the oxygen pumped into the furnace limited impurities, primarily nitrogen, that previously had entered from the air used. Today, electric arc furnaces (EAF) are a common method of reprocessing scrap metal to create new steel. They can also be used for converting pig iron to steel, but they use a lot of electrical energy (about 440 kWh per metric ton), and are thus generally only economical when there is a plentiful supply of cheap electricity.
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Suggested Reading: US trade deficit expands to $47.1 billion in February
SEKO Machinery‘s Culture Wall
Printing on the wall of our products, various styles of Stainless Steel Pipe Making Machine/Tube Mill, also have employees carnival scenes, all kinds of party (the Spring Festival gala, birthday party and celebration dinner).
This is our “Corporate Culture Wall”, it fully reflects SEKO Machinery’s culture. For example,
1、 Corporate Responsibility: Create value for customers, set stage for staff, make a contribution for the society;
2、 Values: Customer first, Teamwork, S.Q.C.D（Safety 、Quality 、Cost 、Delivery）, Embrace Change, Be credible& dedicated;
3、 Annual Slogan: Develop an excellent team& Improve its execution capability;
4、 Aspiration: Develop SEKO Machinery as a sustainable century corporation;
5、 Mission: Let SEKO Machinery win acclaim from the world;
6、 Service Concepts: Respect, Scientific, Efficient;
7、 Corporate Positioning: one-stop service platform of high-end industrial.
Welcome to China, and welcome to Guangdong SEKO Machinery Company to visit our welded pipe making machine, enjoy our culture!
Skype:Lucy Xie,SEKO Machinery
Suggested Reading: Modern steelmaking process (2)
In the spring of vitality
Recently the weather becomes warm and moist, the ceaseless light rain, a spring breeze gently blowing over the earth, and all things fluffs that has been existing body, stretches out his arms and play a yawn, activity exercise began to recover, for spring is coming. Vegetation recovery in the world to reproduce, full of vitality everywhere!
We can see a lot of flowers in Guangdong, the most common flowers are pink azalea, yellow rape flower and red kapok(kapok can also be used to cook porridge and soup, have profit to the body), of course there are all kinds of green plants. Colorful, in southern China in spring is very charming.
It's so great. So I ask my partner take photos with me. Here's our take pictures of about spring around the SEKO Machinery Company, please enjoy. And welcome to SEKO to watch the beautiful spring!
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Suggested Reading: SEKO Machinery‘s Culture Wall
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