A brief introduction to NdFeB (neodymium) magnet, “the magnet king”

A brief introduction to NdFeB (neodymium) magnet, “the magnet king”

A brief introduction to NdFeB (neodymium) magnet, the magnet king

 

NdFeB (neodymium magnet), simply speaking, is a kind of magnet, but unlike most of the magnets we see, it’s called “the magnet king” because of its excellent magnetic properties. NdFeB are praseodymium metal, boron iron and other alloys, it is also called magnetic steel. NdFeB contains a large amount of rare earth element neodymium, iron and boron to form the Nd2Fe14B tetragonal crystalline structure. so it is hard and brittle in character.

 

Molecular structure

Characteristics

Because the surface is easy to be oxidized corrosion, NdFe must be coated on the surface. Surface chemical passivation is one of the best solutions. As a kind of rare earth permanent magnet, NdFeB has the advantages of extremely high magnetic energy product, high coercive force, and high energy density at the same time, which is widely used in modern industry and electronic technology. So NdFeB makes it possible for the instruments and meters, electronic motor, magnetization of the magnetic separation equipment to be minimized, lightweighted, thinned.

 

Applications

Neodymium magnets have replaced alnico and ferrite magnets in many of the myriad applications in modern technology where strong permanent magnets are required, because their greater strength allows the use of smaller, lighter magnets for a given application. Some examples are:

  • Head actuators for computer hard disks
  • Mechanical e-cigarette firing switches
  • Locks for doors
  • Loudspeakers and headphones
  • Mobile phone speakers, taptic feedback and auto focus actuators
  • Magnetic bearings and couplings
  • Benchtop NMR spectrometers
    • Electric motors: (Using neodymium magnets in electric motors can reduce their power consumption by half.)
    • Cordless tools
    • Servomotors
    • Lifting and compressor motors
    • Synchronous motors
    • Spindle and stepper motors
    • Electrical power steering
    • Drive motors for hybrid and electric vehicles. The electric motors of each Toyota Prius require one kilogram (2.2 lb) of neodymium.
  • Actuators
  • Electric generators for wind turbines (only those with permanent magnet excitation)
  • Alignment of nanocellulose chiral nematic suspensions to fabricate cellulose nanocrystals films with tuneable specular and off-specular optical response
  • Voice coil
  • Retail media case decouplers[clarification needed]
  • In process industries, powerful neodymium magnets are used to catch foreign bodies and protect product and processes

 

Grades

Neodymium magnets are graded according to their maximum energy product, which relates to the magnetic flux output per unit volume. Higher values indicate stronger magnets. For sintered NdFeB magnets, there is a widely recognized international classification. Their values range from 28 up to 52. The first letter N before the values is short for neodymium, meaning sintered NdFeB magnets. Letters following the values indicate intrinsic coercivity and maximum operating temperatures (positively correlated with the Curie temperature), which range from default (up to 80 ℃ or 176 ℉) to AH (230℃ or 446 ℉).

Grades of sintered NdFeB magnets:

N30 – N52

N30M – N50M

N30H – N50H

N30SH – N48SH

N30UH – N42UH

N28EH – N40EH

N28AH – N35AH

Magnetic properties of various grades of NdFeB materials

Material Remanence (minimum) Coercivity (minimum) Coercivity (minimum) Maximum Magnetic Energy Product Density Temperature Coefficient Curie Maximum Service Temperature Recoil
Temperature Permeability
Grade Br Hcj Hcb (BH)max D αBr αHcj Tc Tw μrec
Gs mT Oe KA/m Oe KA/m MGOe KJ/m3 g/m3 %/ ℃ %/ ℃
N42 12800~13300 1280~1330 12000 955 11600 923 40~43 318~342 7.5 -0.12 -0.6 320 80 1.05
N45 13300~13700 1330~1370 12000 955 11000 876 43~46 342~366 7.5 -0.12 -0.6 320 80 1.05
N48 13700~14200 1370~1420 12000 955 11200 892 46~49 366~390 7.5 -0.12 -0.6 320 80 1.05
N50 13900~14400 1390~1440 11000 876.00 10500 836.00 47~51 374~406 7.55 -0.12 -0.6 320 80 1.05
N52 14200~14700 1420~1470 11000 876.00 10500 836.00 49~53 390~422 7.55 -0.12 -0.6 320 80 1.05
N42M 12800~13300 1280~1320 14000 1114.00 12000 955.00 40~43 318~342 7.5 -0.12 -0.6 320 100 1.05
N45M 13300~13700 1330~1370 14000 1114.00 12500 995.00 43~46 342~366 7.5 -0.12 -0.6 320 100 1.05
N48M 13600~14200 1360~1420 14000 1114.00 12800 1019.00 45~49 358~390 7.55 -0.12 -0.6 320 100 1.05
N50M 13900~14400 1390~1440 14000 1114.00 13000 1035.00 47~51 374~406 7.55 -0.12 -0.6 320 100 1.05
N52M 14200~14700 1420~1470 13000 1035.00 12500 995.00 49~53 390~422 7.55 -0.12 -0.6 320 100 1.05
N42H 12800~13300 1280~1330 17000 1353.00 12000 955.00 40~43 318~342 7.55 -0.12 -0.6 320 120 1.05
N45H 13300~13700 1330~1370 17000 1353.00 12100 963.00 43~46 342~366 7.55 -0.12 -0.6 320 120 1.05
N48H 13600~14200 1360~1420 17000 1353.00 12900 1027.00 45~49 358~390 7.6 -0.12 -0.6 320 120 1.05
N50H 13900~14400 1390~1440 16000 1274.00 13000 1035.00 47~51 374~406 7.6 -0.12 -0.6 320 120 1.05
N42SH 12800~13200 1280~1320 20000 1592.00 12200 971.00 40~43 318~342 7.55 -0.11 -0.55 320 150 1.05
N45SH 13200~13700 1320~1370 20000 1592.00 12300 979.00 43~46 342~366 7.6 -0.11 -0.55 320 150 1.05
N48SH 13600~14200 1360~1420 19000 1512.00 12500 995.00 45~49 358~390 7.6 -0.11 -0.55 320 150 1.05
N28UH 10200~10800 1020~1080 25000 1990.00 9600 764.00 26~29 207~231 7.5 -0.1 -0.51 320 180 1.05
N30UH 10800~11300 1080~1130 25000 1990.00 10200 812.00 28~31 223~247 7.5 -0.1 -0.51 320 180 1.05
N33UH 11300~11700 1130~1170 25000 1990.00 10700 852.00 31~34 247~271 7.55 -0.1 -0.51 320 180 1.05
N35UH 11700~12200 1170~1220 25000 1990.00 10800 860.00 33~36 263~287 7.55 -0.1 -0.51 320 180 1.05
N38UH 12200~12500 1220~1250 25000 1990.00 11000 876.00 36~39 287~310 7.6 -0.1 -0.48 320 180 1.05
N40UH 12500~12800 1250~1280 25000 1990.00 11500 915.00 38~41 302~326 7.6 -0.1 -0.48 320 180 1.05
N42UH 12700~13200 1270~1320 24000 1910.00 12200 971.00 39~43 310~342 7.6 -0.1 -0.48 320 180 1.05
N45UH 13200~13700 1320~1370 24000 1910.00 12300 979.00 43~46 342~366 7.6 -0.1 -0.48 320 180 1.05
N28EH 10400~10900 1040~1090 30000 2388.00 9800 780.00 26~29 207~231 7.6 -0.09 -0.48 320 200 1.05
N30EH 10800~11300 1080~1130 30000 2388.00 10200 812.00 28~31 223~247 7.6 -0.09 -0.48 320 200 1.05
N33EH 11300~11700 1130~1170 30000 2388.00 10300 820.00 31~34 247~271 7.6 -0.09 -0.48 320 200 1.05
N35EH 11700~12200 1170~1220 30000 2388.00 10500 836.00 33~36 263~287 7.6 -0.09 -0.48 320 200 1.05
N38EH 12000~12500 1200~1250 30000 2388.00 11500 915.00 35~39 279~310 7.6 -0.09 -0.48 320 200 1.05
N28AH 10200~10900 1020~1090 34000 2706.00 9800 780.00 25~29 199~231 7.6 -0.09 -0.48 320 240 1.05
N30AH 10700~11300 1070~1130 34000 2706.00 10200 812.00 27~31 215~247 7.6 -0.09 -0.48 320 240 1.05
N33AH 11100~11700 1110~1170 34000 2706.00 10300 820.00 30~34 239~271 7.6 -0.09 -0.48 320 240 1.05
N35AH 11700~12200 1170~1220 34000 2706.00 10500 836.00 32~36 255~287 7.6 -0.09 -0.48 320 240 1.05

The largest deposit and reserve of rare earth is in Bayan’obo mine, Inner Mondolia, China.  Baotou bayan’obo mine is the largest rare earth mine in the world.

A brief introduction to Inner Mongolia, China, the largest deposit and producer of rare earth and mineral resources

A brief introduction to Inner Mongolia, China, the largest deposit and producer of rare earth and mineral resources

A brief introduction to Inner Mongolia, China, the largest deposit and producer of rare earth and mineral resources

Inner Mongolia, located in the northern part of China, is a narrow-long province bordered with Mongolia and Russia in its northern direction. Capital of Inner Mongolia is Hohhot while major cities are Ordos, Baotou and Chifeng. Inner Mongolia is rich in resource reserves, known as “east forest, west ore, south agriculture and north animal husbandry”. The grassland, forest and per capita cultivated land area of Inner Mongolia ranks the first in China. The reserve of rare earth metals ranks the first in the world.

 

Basic Information

Chinese Name: 内蒙古

Location:Inner Mongolia is in the northern China, its great stretch means that parts of it belong to Northeast China and Northwest China as well

Provincial capital: Hohhot

Area: 1,183,000 km2 (457,000 sq mi)

Famous Cities: Hohhot, Baotou, Ordos, Hunlun Buir

Population: Inner Mongolia is a multi-minority province. Mainly dwelling with Han (Chinese) group. The largest minority lived in this province is the Mongols. Other minorities include the Hui (Chinese Muslims), Manchu, Daur (Dawo’er) Mongols, Evenk (Ewenki, or Ewenke), Koreans, and Oroqen (Elunchun) peoples.

 

Animal Husbandry Resources

Inner Mongolia Horses

Inner Mongolia is an important animal husbandry production base in China. The total grassland area is 866.67 million hectares, of which 68 million hectares are available grassland, accounting for a quarter of the total grassland area in China. By 2010, there are a total of six famous prairies, and they are Inner Mongolia Hulun Buir, Xilingol, Khorchin, Wulanchabu, Ordos and Wulagai prairies. On them grows 1000 feeding plants, and more than 100 feeding plants with high feeding value and strong palatability. In particular, grasses such as leymus, festuca, ice grass, soda-grass, wild oat and legume grass are very suitable for raising livestock.

 

Mineral Resources

Baiyan'obo mine

The Inner Mongolia autonomous region is the province where most new minerals are found in China. Since 1958, China has obtained international recognition of more than 50 new minerals, of which 10 are found in Inner Mongolia, including NdFeB magnete material, barium-ferrite, Baotou ore, Yellow River ore, saolun stone, mercury lead ore, xing’an stone, Daqingshan ore, Xilingol ore, Erlian stone and Bayan’obo ore. Thanks for its rich iron ore, Baotou Steel has developed into the top 5 manufacruer and supplier of seamless steel pipes and other products in China. Baotou bayan’obo mine is the largest rare earth mine in the world. Baiyun obo mine of baotou iron & steel group co., LTD. is a remarkable multi-metal ore of iron, rare earth, niobium and thorium, etc. It is the largest iron deposit in northwest China, ranking first in rare earth reserves and second in niobium and thorium reserves. By 1997, proved reserves of rare earth oxides accounted for 76% of the world’s total, including Y2O3, HO2O3, Dy2O3, Eu2O3, Tb2O3, CeO2, La2O3, Pr6O11, (PrNd)xOy, etc. The mine contains 172 kinds of minerals, making it the mine with the largest number of mineral species in the world. By 2006, 135 kinds of minerals had been discovered and 83 kinds of proved reserves were found, 5 kinds of minerals with the largest reserves in China, 28 kinds of minerals with the top three kinds in China and 67 kinds of minerals with the top ten kinds in China. Rare earth reserves are the world’s largest, with coal reserves of 701.6 billion tons, the largest in China, and natural gas reserves of 790.3 billion cubic meters. The sulige gas field in the Ordos basin is one of the few onshore super-large gas fields discovered in China as of 2010. The total power from wind energy is 101 million kilowatts, ranking first in China.

 

API 5CT standard petroleum borewell seamless steel casing pipe for oil drilling

API 5CT standard petroleum borewell seamless steel casing pipe for oil drilling

Definition

The oil casing is a kind of steel pipe used to support the well wall of oil and gas wells, so as to ensure the normal operation of the whole oil well during the drilling process and after the completion of the well. According to different drilling depth and geological conditions, several layers of casing shall be used for each well. After casing running into the well, cement should be used for cementing. It is different from tubing and drill pipe, and can not be reused. It belongs to disposable consumption material. Therefore, the consumption of casing accounts for more than 70% of all oil well pipes.

 

Casing can be divided into: conduit, surface casing, technical casing and reservoir casing according to the usage.

 

Different well conditions and well depths lead to different steel grades. In corrosive environment, the casing itself is also required to have corrosion resistance ability. In the complex geological conditions, casing is also required to have collapse resistance ability.According to API 5CT,there are three kinds of casing lengths: R1 is 4.88-7.62m, R2 is 7.62-10.36m, and R3 is 10.36m and longer.

 

 

Application:

The oil casing is a kind of large-diameter pipe, which is used to fix the oil and natural gas wellbore or hole.The casing is inserted into the hole and held in place with cement to help the well block the rock and prevent the hole from collapsing, while allowing drilling mud to circulate for easy drilling.

 

Steel grades of oil casing: H40, J55, K55, N80, L80, C90, T95, P110, Q125, V150, etc.Thread types: short round thread casing(STC), long round thread casing(LC), buttress thread casing (BTC),partial trapezoidal thread casing and special buckle casings such as BT-1 thread casing,BT-2 thread casing,BT-3 thread casing,vam top thread casing,new vam thread casing and OTTM thread casing,etc.

API 5CT standard petroleum borewell seamless steel casing pipe for oil drilling

              Appearances of steel casing pipes of different steel grades

 

 

 

 

 

 

                                                                                                                                                                                                                                                                                                                                                                                                                                                    

   

API 5CT standard petroleum borewell seamless steel casing pipe for oil drilling

Species:

API 5CT establishes requirements for three product specification levels (PSL-1, PSL-2, PSL-3). The requirements for PSL-1 are the basis of this standard.

 

Different types of casing used in the production of oil: surface casing protects the well from contamination by shallow water and gas, supports wellhead equipment and maintains the weight of other layers of casing.Technology oil casing separates the pressure at different levels so that the drilling fluid line can flow normally and protect the production casing.For installation of anti-blowout, leak preventer and liner in the well.The reservoir casing carries oil and gas out of the reservoir below the surface.Used to protect the well and to layer the drilling mud.The outer diameter of the casing is usually 114.3 mm to 508 mm.

 

 

 

A brief introduction to Chinese GB standard Q345 series of seamless steel pipes

A brief introduction to Chinese GB standard Q345 series of seamless steel pipes

A brief introduction to Chinese GB standard Q345 series seamless steel pipes

 

Defination of Q345

Q345 steel, with charicteristics of 7.85 g/cm3 material density, and 470-630 Mpa tensile strength, is a Chinese GB standard low alloy high strength structural steel. “Q” is the first letter of Chinese Pinyin: “qu fu dian”, which means Yield Point, “345” is the minimum value of yield strength for steel thickness less than 16mm. It is commonly used material among low alloy materials, and it was called 16Mn in the past.

 

Quality Grades

It has 5 quality grades: Q345A, Q345B, Q345C, Q345D and Q345E. These five grades are mainly different in whether steel pipe need to be impact tested and impact test temperture. Q345A don’t need to be tested; Q345B need to be test at 20℃(also called room temperature), Q345C need to be test at 0℃, Q345D need to be test at -20℃ and Q345E need to be test at- 40℃.

 

Application

Q345 steel has good weldability, cold & hot workability and corrosion resistance. Widely used in bridges, ships, boilers, pressure vessels, petroleum storage tanks, lifting transport machinery and other high-load welded structural parts.

 

Chemical Composition

Chemical Composition Content (≤%) ≥%
Steel Grade Quality Grade C Si Mn P S Nb V Ti Cr Ni Cu N Mo B Als
Q345 Q345A 0.20 0.50 1.70 0.035 0.035 0.07 0.15 0.20 0.30 0.50 0.30 0.012 0.10
Q345B 0.035 0.035
Q345C 0.030 0.030 0.015
Q345D 0.18 0.030 0.025
Q345E 0.025 0.020

Notes: The P and S contents of profiles and bars can be increased by 0.005%, and the upper limit of Grade A steel can be 0.0045%.

 

Mechanical Properties

Mechanical Properties: Yield Strength (≥ N/mm2)
Steel Grade Quality Grade Ø ≤16 16 < Ø ≤ 40 40 < Ø ≤ 63 63 < Ø ≤ 80 80 < Ø ≤ 100 100 < Ø ≤ 150 150 < Ø ≤ 200 200 < Ø ≤ 250 250 < Ø ≤ 400
Q345 Q345A ≥345 ≥335 ≥325 ≥315 ≥305 ≥285 ≥275 ≥265
Q345B
Q345C
Q345D ≥265
Q345E

Notes: Ø = Thickness or wire diameter in mm;

1 MPa = 1 N/mm2

Mechanical Properties: Tensile Strength (N/mm2)
Grade Quality Level Ø ≤ 40 40 < Ø ≤ 63 63 < Ø ≤ 80 80 < Ø ≤ 100 100 < Ø ≤ 150 150 < Ø ≤ 250 250 < Ø ≤ 400
Q345 Q345A 470 – 630 470 – 630 470 – 630 470 – 630 450 – 600 450 – 600
Q345B
Q345C
Q345D 450 – 600
Q345E

 

Ø mm, Elongation (≥%)
Grade Quality Level Ø ≤40 40 < Ø ≤ 63 63 < Ø ≤ 100 100 < Ø ≤ 150 150 < Ø ≤ 250 250 < Ø ≤ 400
Q345 Q345A ≥20 ≥19 ≥19 ≥18 ≥17
Q345B
Q345C ≥21 ≥20 ≥20 ≥19 ≥18
Q345D ≥17
Q345E

Charpy Impact

Charpy (V-notch) impact test temperature and impact absorption energy (KV2/J), thickness (t).

Quality Temperature, ℃ 12-150 (mm) 150<t≤250 (mm) 250<t≤400 (mm)
Q345B 20 ≥34J ≥27J
Q345C 0
Q345D -20 27J
Q345E -40