Monthly Archives: March 2025

　　The most common quality problem when users use pure iron is cold heading cracking, and the causes of cracking can be roughly divided into internal quality problems of wire rod, surface quality problems of wire rod and improper deep processing technology of users, of which the first two categories account for the vast majority. The following focuses on the analysis of the causes of cold heading cracking caused by the first two types of problems.Under people’s attention Pure Iron Billets Finally grow into what people need, born for the market and come for the demand. https://www.slhpureiron.net

　　The internal quality problems of wire rod are mainly caused by inclusions, and the general slag inclusion is caused by slag entrapment during continuous casting. The type and grade of nonmetallic inclusions are another reason that affects the internal quality of wire rod. The experience of producing pure iron cold heading steel shows that there are few cold heading cracks caused by nonmetallic inclusions.

　　Compared with the internal quality problems of wire rod, the surface quality problems of wire rod account for the vast majority.

　　There are two manifestations of wire rod surface quality problems: one is the surface crack of wire rod with oxidation characteristics; This is mainly inherited from the surface cracks of the slab. Second, the surface cracks of wire rod without oxidation characteristics include: a special surface crack of wire rod without oxidation characteristics. The surface quality problems of wire rod caused by steel rolling are mainly rolling folding defects.

　　Measures taken:

　　First, steelmaking and continuous casting

　　Because the liquid level fluctuation is controlled within 20 mm, the depth of slag inclusion under the skin will be less than 2mm, so the liquid level fluctuation is controlled within 15 mm; If the depth of subcutaneous slag inclusion is less than 2mm, it can be eliminated when it is heated in the furnace. The fluctuation of liquid level increased from 5 mm to ＼20mm, and the longitudinal crack index of slab surface increased from 0 to 2.0. Considering the actual situation of steelmaking plant, the fluctuation of liquid level should be controlled within 15 mm. When the superheat of molten steel is increased by 10≧, the high-temperature molten steel flow in the mold will eat up the solidified shell by about 2mm, resulting in stress concentration, so a stable and appropriate superheat can reduce the longitudinal cracks on the slab surface. Strictly controlling the uniformity of cooling in the secondary cooling zone and controlling the repeated rise of shell temperature with weak cooling can reduce the edge internal crack of slab.

　　Second, steel rolling

　　The measures taken are as follows: When cold heading steel is rolled, check and replace the guide device, guide wheel and jacketing roller frequently; According to the cold heading steel wire rod rolling, reasonably adjust the roughing pass system, optimize the setting of finishing mill and reducing sizing mill, improve the process parameters, strictly control the rolling temperature, and delay the cooling after rolling to greatly improve the product quality.

WWW.SLHPUREIRON.COM

SLH Pure Iron

SHANXI SHENG LONG HUA MAGNETIC MATERIAL CO.,LTD

Email: sales@slhpureiron.com

WhatsApp: +86 13410953850

WeChat: SLHPUREIRON

　　The preparation of nano-materials has always been a research hotspot and a research difficulty in the field of nano-technology. Although a variety of preparation methods of nano-materials have been developed, and great progress has been made in their preparation technology, due to the complex preparation process, high cost, small material size, internal holes and pollution, it is difficult to obtain integral metal materials with nano-particle size so far.In order to achieve the goal, Armco Iron Turn cocoon into butterfly, constantly polish product quality, improve business ability, and finally have a place in the market. https://www.slhpureiron.net

　　Therefore, how to prepare nano-materials with fewer defects by simpler and lower-cost means has become the pursuit goal in this field. In recent years, surface mechanical abrasion treatment (SMAT) has become a new method for preparing nano-materials. The nanocrystalline samples obtained by this method have a grain size within 100nm in a certain depth of the surface layer, and have a gradient structure of gradual transition between nano-,sub-micron and deformed grain layers, and are pollution-free and void-free.

　　Nanomaterials prepared by SMAT method have many potential application values because of the above characteristics, and have been applied in diffusion welding, surface alloying and nitriding. Self-nanocrystallization of various metals and alloys has been successfully achieved by SMAT method. Ultrasonic shot peening (USSP) is widely used in the preparation of nanomaterials by SMAT method, while Highenergyshotpeening,HESP (HESP) is seldom used.

　　Although some people have realized the surface self-nanocrystallization of pure iron by USSP, there is no report on the surface self-nanocrystallization of pure iron by HESP method. A severely plastic deformation layer with a certain thickness was obtained on the surface of industrial pure iron by HESP method.

　　By analyzing and characterizing the structure and properties of this severely plastic deformation layer, it was confirmed that a nanocrystalline layer with a certain thickness was obtained on the surface of industrial pure iron, and the surface of industrial pure iron was self-nanocrystallized.

WWW.SLHPUREIRON.COM

SLH Pure Iron

SHANXI SHENG LONG HUA MAGNETIC MATERIAL CO.,LTD

Email: sales@slhpureiron.com

WhatsApp: +86 13410953850

WeChat: SLHPUREIRON

　　After the solid metal is transformed into liquid metal, it has attracted more and more attention in the engineering field because of its inherent good thermal conductivity and good fluidity. Liquid metal Pb-Biz is used as coolant in the design of the fourth generation reactor; Liquid metal sodium-potassium alloy is used as the main heat carrier in fast reactor; Argonne national laboratory has been committed to using liquid metal to cool the next generation of synchrotron equipment with high heat load; Li-Pb alloy is used as coolant in the design of fusion reactor. Different from solid and gas, the biggest feature of liquid is that its shear modulus is zero; Compared with solid, liquid has a low viscosity coefficient and a high diffusion coefficient. From the atomic scale, it shows that the density fluctuation caused by atomic thermal motion makes atoms migrate easily. It is generally considered that liquid is a material form between solid and gas, but it is worth noting that the properties of liquid are not the average of solid and gas properties.Not only does it perform well in data, Pure Iron Billets In the market share, it is also gradually expanding, so that more people can benefit. https://www.slhpureiron.net

　　Self-diffusion coefficient of liquid pure iron

　　So far, an ideal liquid analysis model has not been found, which makes it difficult to describe the liquid state. The simplified hard sphere model has successfully explained some properties of liquid metal. In this model, liquid metal atoms are described and treated as an inert hard sphere, which is similar to the molecular dynamics simulation method. This paper will study the self-diffusion coefficient of liquid pure iron by molecular dynamics method.

　　Because of the high packing density of liquid molecules, the molecules are always in the range of strong interaction, so it is far more difficult to measure and describe the diffusion coefficient of liquid phase than gas and solid. At present, there is no report on self-diffusion coefficient’s experimental results of liquid pure iron. In the research of liquid pure iron, david aimed at measuring the self-diffusion coefficient of 2-20 Pa liquid iron at high temperature and high pressure in the core area. Jang et al. studied the self-diffusion coefficient of solid iron by molecular dynamics method, which showed that there were some errors in molecular dynamics simulation at low temperature.

WWW.SLHPUREIRON.COM

SLH Pure Iron

SHANXI SHENG LONG HUA MAGNETIC MATERIAL CO.,LTD

Email: sales@slhpureiron.com

WhatsApp: +86 13410953850

WeChat: SLHPUREIRON

　　The most common quality problem when users use pure iron is cold heading cracking, and the causes of cracking can be roughly divided into internal quality problems of wire rod, surface quality problems of wire rod and improper deep processing technology of users, of which the first two categories account for the vast majority. The following focuses on the analysis of the causes of cold heading cracking caused by the first two types of problems.in fact High purity Iron Our related products were once praised by users, which is the best self-affirmation of the products. https://www.slhpureiron.net

　　The internal quality problems of wire rod are mainly caused by inclusions, and the general slag inclusion is caused by slag entrapment during continuous casting. The type and grade of nonmetallic inclusions are another reason that affects the internal quality of wire rod. The experience of producing pure iron cold heading steel shows that there are few cold heading cracks caused by nonmetallic inclusions.

　　Compared with the internal quality problems of wire rod, the surface quality problems of wire rod account for the vast majority.

　　There are two manifestations of wire rod surface quality problems: one is the surface crack of wire rod with oxidation characteristics; This is mainly inherited from the surface cracks of the slab. Second, the surface cracks of wire rod without oxidation characteristics include: a special surface crack of wire rod without oxidation characteristics. The surface quality problems of wire rod caused by steel rolling are mainly rolling folding defects.

　　Measures taken:

　　First, steelmaking and continuous casting

　　Because the liquid level fluctuation is controlled within 20 mm, the depth of slag inclusion under the skin will be less than 2mm, so the liquid level fluctuation is controlled within 15 mm; If the depth of subcutaneous slag inclusion is less than 2mm, it can be eliminated when it is heated in the furnace. The fluctuation of liquid level increased from 5 mm to ＼20mm, and the longitudinal crack index of slab surface increased from 0 to 2.0. Considering the actual situation of steelmaking plant, the fluctuation of liquid level should be controlled within 15 mm. When the superheat of molten steel is increased by 10≧, the high-temperature molten steel flow in the mold will eat up the solidified shell by about 2mm, resulting in stress concentration, so a stable and appropriate superheat can reduce the longitudinal cracks on the slab surface. Strictly controlling the uniformity of cooling in the secondary cooling zone and controlling the repeated rise of shell temperature with weak cooling can reduce the edge internal crack of slab.

　　Second, steel rolling

　　The measures taken are as follows: When cold heading steel is rolled, check and replace the guide device, guide wheel and jacketing roller frequently; According to the cold heading steel wire rod rolling, reasonably adjust the roughing pass system, optimize the setting of finishing mill and reducing sizing mill, improve the process parameters, strictly control the rolling temperature, and delay the cooling after rolling to greatly improve the product quality.

WWW.SLHPUREIRON.COM

SLH Pure Iron

SHANXI SHENG LONG HUA MAGNETIC MATERIAL CO.,LTD

Email: sales@slhpureiron.com

WhatsApp: +86 13410953850

WeChat: SLHPUREIRON

　　The preparation of nano-materials has always been a research hotspot and a research difficulty in the field of nano-technology. Although a variety of preparation methods of nano-materials have been developed, and great progress has been made in their preparation technology, due to the complex preparation process, high cost, small material size, internal holes and pollution, it is difficult to obtain integral metal materials with nano-particle size so far.So, Cathode Flat On the contrary, there is still a lot of room to play. https://www.slhpureiron.net

　　Therefore, how to prepare nano-materials with fewer defects by simpler and lower-cost means has become the pursuit goal in this field. In recent years, surface mechanical abrasion treatment (SMAT) has become a new method for preparing nano-materials. The nanocrystalline samples obtained by this method have a grain size within 100nm in a certain depth of the surface layer, and have a gradient structure of gradual transition between nano-,sub-micron and deformed grain layers, and are pollution-free and void-free.

　　Nanomaterials prepared by SMAT method have many potential application values because of the above characteristics, and have been applied in diffusion welding, surface alloying and nitriding. Self-nanocrystallization of various metals and alloys has been successfully achieved by SMAT method. Ultrasonic shot peening (USSP) is widely used in the preparation of nanomaterials by SMAT method, while Highenergyshotpeening,HESP (HESP) is seldom used.

　　Although some people have realized the surface self-nanocrystallization of pure iron by USSP, there is no report on the surface self-nanocrystallization of pure iron by HESP method. A severely plastic deformation layer with a certain thickness was obtained on the surface of industrial pure iron by HESP method.

　　By analyzing and characterizing the structure and properties of this severely plastic deformation layer, it was confirmed that a nanocrystalline layer with a certain thickness was obtained on the surface of industrial pure iron, and the surface of industrial pure iron was self-nanocrystallized.

WWW.SLHPUREIRON.COM

SLH Pure Iron

SHANXI SHENG LONG HUA MAGNETIC MATERIAL CO.,LTD

Email: sales@slhpureiron.com

WhatsApp: +86 13410953850

WeChat: SLHPUREIRON

　　The preparation of nano-materials has always been a research hotspot and a research difficulty in the field of nano-technology. Although a variety of preparation methods of nano-materials have been developed, and great progress has been made in their preparation technology, due to the complex preparation process, high cost, small material size, internal holes and pollution, it is difficult to obtain integral metal materials with nano-particle size so far.The above conclusions show that Cathode Flat To a great extent, it can bring new vitality to the market and make the industry develop well. https://www.slhpureiron.net

　　Therefore, how to prepare nano-materials with fewer defects by simpler and lower-cost means has become the pursuit goal in this field. In recent years, surface mechanical abrasion treatment (SMAT) has become a new method for preparing nano-materials. The nanocrystalline samples obtained by this method have a grain size within 100nm in a certain depth of the surface layer, and have a gradient structure of gradual transition between nano-,sub-micron and deformed grain layers, and are pollution-free and void-free.

　　Nanomaterials prepared by SMAT method have many potential application values because of the above characteristics, and have been applied in diffusion welding, surface alloying and nitriding. Self-nanocrystallization of various metals and alloys has been successfully achieved by SMAT method. Ultrasonic shot peening (USSP) is widely used in the preparation of nanomaterials by SMAT method, while Highenergyshotpeening,HESP (HESP) is seldom used.

　　Although some people have realized the surface self-nanocrystallization of pure iron by USSP, there is no report on the surface self-nanocrystallization of pure iron by HESP method. A severely plastic deformation layer with a certain thickness was obtained on the surface of industrial pure iron by HESP method.

　　By analyzing and characterizing the structure and properties of this severely plastic deformation layer, it was confirmed that a nanocrystalline layer with a certain thickness was obtained on the surface of industrial pure iron, and the surface of industrial pure iron was self-nanocrystallized.

WWW.SLHPUREIRON.COM

SLH Pure Iron

SHANXI SHENG LONG HUA MAGNETIC MATERIAL CO.,LTD

Email: sales@slhpureiron.com

WhatsApp: +86 13410953850

WeChat: SLHPUREIRON

　　Ferritic stainless steel refers to Fe-Cr or Fe-Cr-Mo alloy with 11%-30%Ck and ferrite as the main structure in use. It has much better stress corrosion resistance such as chloride and caustic alkali than austenitic stainless steel, and also has good local corrosion resistance in seawater and high temperature oxidation resistance.In the eyes of industry experts, Cathode Flat Indeed, it has great development potential, which makes many investors more interested. https://www.slhpureiron.net

　　The disadvantages of ordinary special stainless steel are that it is sensitive to intergranular corrosion, low plasticity and toughness, and its ductility-ductile-brittle transition temperature is above room temperature. Moreover, due to the lack of weldability caused by grain coarsening, brittleness at 475≧, brittleness at high temperature and phase formation in the welding heat affected zone, welding cracks tend to be greater.

　　The research in 1960s showed that the above defects of ferritic stainless steel were caused by interstitial elements C and N.. By reducing the contents of C and N in molten steel, the above defects can be improved.

　　Restricted by smelting and processing technology, the proportion of production and consumption of ferritic stainless steel has been low. In 2003, the global output of crude stainless steel was 22.8 million tons, with 400 series stainless steel accounting for about 21%. In 2003, the output of stainless steel in China was about 1.778 million tons, with 400 series stainless steel accounting for about 10%.

　　In recent years, the development and application of ferritic stainless steel has been paid more and more attention at home and abroad. The main reasons are as follows: 1. The serious shortage of Ni resources and the large fluctuation of Ni price have led to a sharp increase in the production cost of 300 series stainless steel, and the supply of raw materials is not guaranteed; 2. With the progress of production equipment and technology, ferritic stainless steel with excellent performance can be produced to replace some varieties of 300 series; 3. Stainless steel containing Ni is harmful to human body, such as allergic reaction to skin.

　　Ultra-pure ferritic stainless steel is mainly used in automobile manufacturing, kitchen equipment, household appliances, architectural decoration, chemical equipment and hardware products.

WWW.SLHPUREIRON.COM

SLH Pure Iron

SHANXI SHENG LONG HUA MAGNETIC MATERIAL CO.,LTD

Email: sales@slhpureiron.com

WhatsApp: +86 13410953850

WeChat: SLHPUREIRON

　　Ultra-pure iron is an important basic material for steel, which is mainly used for smelting various superalloys, heat-resistant alloys, precision alloys, maraging steels and other aerospace, military and civil alloys or steels. In recent years, it has developed extremely rapidly at home and abroad. Developing the preparation technology of high-purity iron can expand its application range.On the other hand, Armco Iron It also brings tangible benefits to everyone and feels useful. It is a model of the industry. https://www.slhpureiron.net

　　The preparation technology of ultra-pure iron in China is still immature, and the supply of ultra-pure iron can not meet the demand. However, it is studied to smelt ultra-pure iron with sponge iron as iron source in induction furnace. From the raw material point of view, the output of sponge iron is increasing and the price is relatively cheap. In terms of composition, the content of residual elements in sponge iron is low, and the purity of ultra-pure iron products is high.

　　In this paper, under the laboratory conditions, the experimental study on smelting ultra-pure iron with sponge iron in induction furnace was carried out with 25kg medium frequency induction furnace and 25kg vacuum induction furnace. The main research contents include the thermodynamics and kinetics of deep dephosphorization of sponge iron, the selection of dephosphorization slag system and the factors affecting deep dephosphorization of steel, etc. Pure iron with phosphorus content of about 10ppm is smelted from sponge iron in induction furnace.

　　On this basis, the thermodynamic conditions of deep desulfurization of steel are analyzed theoretically, and the effects of composition melting point of desulfurization slag system, mechanical mixed slag and premelted refining slag on desulfurization of steel are studied through experiments. Through theoretical analysis and experimental data, the conditions that must be met for deep desulfurization of molten steel are obtained, and finally the sulfur content in molten steel is reduced to about 10ppm in the induction furnace.

　　It is feasible to smelt ultra-pure iron with sponge iron or direct reduced iron in induction furnace as long as the thermodynamic conditions of dephosphorization and desulfurization are well controlled and the composition of smelting slag system is selected. If it can be applied to large-scale industrial production, it will have a good application prospect.

WWW.SLHPUREIRON.COM

SLH Pure Iron

SHANXI SHENG LONG HUA MAGNETIC MATERIAL CO.,LTD

Email: sales@slhpureiron.com

WhatsApp: +86 13410953850

WeChat: SLHPUREIRON

　　Ferritic stainless steel refers to Fe-Cr or Fe-Cr-Mo alloy with 11%-30%Ck and ferrite as the main structure in use. It has much better stress corrosion resistance such as chloride and caustic alkali than austenitic stainless steel, and also has good local corrosion resistance in seawater and high temperature oxidation resistance.After screening and investigation High purity Iron It is likely to become a new force driving economic development. https://www.slhpureiron.net

　　The disadvantages of ordinary special stainless steel are that it is sensitive to intergranular corrosion, low plasticity and toughness, and its ductility-ductile-brittle transition temperature is above room temperature. Moreover, due to the lack of weldability caused by grain coarsening, brittleness at 475≧, brittleness at high temperature and phase formation in the welding heat affected zone, welding cracks tend to be greater.

　　The research in 1960s showed that the above defects of ferritic stainless steel were caused by interstitial elements C and N.. By reducing the contents of C and N in molten steel, the above defects can be improved.

　　Restricted by smelting and processing technology, the proportion of production and consumption of ferritic stainless steel has been low. In 2003, the global output of crude stainless steel was 22.8 million tons, with 400 series stainless steel accounting for about 21%. In 2003, the output of stainless steel in China was about 1.778 million tons, with 400 series stainless steel accounting for about 10%.

　　In recent years, the development and application of ferritic stainless steel has been paid more and more attention at home and abroad. The main reasons are as follows: 1. The serious shortage of Ni resources and the large fluctuation of Ni price have led to a sharp increase in the production cost of 300 series stainless steel, and the supply of raw materials is not guaranteed; 2. With the progress of production equipment and technology, ferritic stainless steel with excellent performance can be produced to replace some varieties of 300 series; 3. Stainless steel containing Ni is harmful to human body, such as allergic reaction to skin.

　　Ultra-pure ferritic stainless steel is mainly used in automobile manufacturing, kitchen equipment, household appliances, architectural decoration, chemical equipment and hardware products.

WWW.SLHPUREIRON.COM

SLH Pure Iron

SHANXI SHENG LONG HUA MAGNETIC MATERIAL CO.,LTD

Email: sales@slhpureiron.com

WhatsApp: +86 13410953850

WeChat: SLHPUREIRON

　　Wheelchairs are widely used in patients’ rehabilitation training and family life, such as lower limb dysfunction, hemiplegia, paraplegia below the chest and people with mobility difficulties. As patients’ families and rehabilitation therapists, it is very necessary to know the characteristics of wheelchairs, choose the most suitable wheelchairs and use them correctly.The data shows that, 電動輪椅價錢 Its development potential should not be underestimated, and it is also the inevitability of its existence. https://www.hohomedical.com/collections/light-weight-wheelchair

　　First of all, what harm will an inappropriate wheelchair do to the user?

　　Excessive local compression

　　Form a bad posture

　　Induced scoliosis

　　Causing contracture of joints

　　(What are the unsuitable wheelchairs: the seat is too shallow and the height is not enough; The seat is too wide and the height is not enough)

　　The main parts that wheelchair users bear pressure are ischial tubercle, thigh, popliteal fossa and scapula. Therefore, when choosing a wheelchair, we should pay attention to whether the size of these parts is appropriate to avoid skin wear, abrasions and pressure sores.

　　Let’s talk about the choice of wheelchair, which must be kept in mind!

　　Choice of ordinary wheelchair

　　Seat width

　　Measure the distance between two hips or between two legs when sitting down, and add 5cm, that is, there is a gap of 2.5cm on each side after sitting down. The seat is too narrow, it is difficult to get on and off the wheelchair, and the hip and thigh tissues are compressed; The seat is too wide, it is difficult to sit still, it is inconvenient to operate the wheelchair, the upper limbs are easy to get tired, and it is difficult to get in and out of the gate.

　　Seat length

　　Measure the horizontal distance from the hip to the gastrocnemius of the calf when sitting down, and reduce the measurement result by 6.5cm. The seat is too short, the weight mainly falls on the ischium, and the local pressure is easy to be too much; If the seat is too long, it will compress the popliteal fossa, affect the local blood circulation, and easily irritate the skin of this part. It is better to use a short seat for patients with extremely short thighs or flexion and contracture of hips and knees.

　　Seat height

　　Measure the distance from the heel (or heel) to the popliteal fossa when sitting down, and add 4cm. When placing the pedal, the board surface should be at least 5cm from the ground. The seat is too high for the wheelchair to enter the table; The seat is too low and the ischium bears too much weight.

　　seating washer

　　In order to be comfortable and prevent pressure sores, a seat cushion should be placed on the seat, and foam rubber (5~10cm thick) or gel cushion can be used. To prevent the seat from sinking, a piece of plywood with a thickness of 0.6cm can be placed under the seat cushion.

　　Backrest height

　　The higher the backrest, the more stable it is, and the lower the backrest, the greater the range of motion of the upper body and upper limbs. The so-called low backrest is to measure the distance from the seat surface to the armpit (one arm or two arms extend forward horizontally), and subtract 10cm from this result. High backrest: measure the actual height from the seat surface to the shoulder or back pillow.

　　Handrail height

　　When sitting down, the upper arm is vertical and the forearm is flat on the armrest. Measure the height from the chair surface to the lower edge of the forearm, and add 2.5cm. Proper armrest height helps to maintain correct posture and balance, and can make the upper limbs placed in a comfortable position. The armrest is too high, and the upper arm is forced to lift up, which is easy to fatigue. If the armrest is too low, you need to lean forward to maintain balance, which is not only easy to fatigue, but also may affect your breathing.

　　Other auxiliary parts of wheelchair

　　Designed to meet the special needs of patients, such as increasing the friction surface of the handle, extending the brake, anti-shock device, anti-skid device, armrest mounting arm rest, wheelchair table to facilitate patients to eat and write, etc.