Brief introduction of medium and heavy plate manufacturing technology developed and applied by JFE Japan

Although the requirements for the performance of medium-thick steel plates in recent years are largely dependent on the differences in application areas, the performance requirements are getting higher and higher. Specifically, performance requirements involve many aspects, including high strength, improved weldability, and the like. To meet these requirements, precise material design techniques and advanced manufacturing techniques are the essence of the problem.

Based on this situation, Japan JFE Steel Co., Ltd. began to develop a thermo-mechanical control process (TMCP) using water quenching as a core technology for high-strength, high-toughness and excellent welding performance steel sheet production technology. The following is a brief introduction to the plate manufacturing technology developed and applied by JFE Steel, including Super-OLAC technology, a new medium plate accelerated cooling technology and HOP technology (heat treatment online process), an in-line heat treatment after accelerated cooling. Process. At the same time, the Easyfab steel sheet manufacturing technology is described below, which reduces the residual stress in the medium and heavy plates to zero by applying a cold straightening machine with new functions.

First, the new accelerated cooling technology - the development of "super-OLAC" technology

Together with controlled rolling technology, accelerated cooling technology is the core technology of the TMCP process. JFE Steel is the world's first steel company to develop and successfully apply online accelerated cooling technology to plate production.

In the early 1990s, TMCP steel manufactured by accelerated cooling technology achieved the purpose of improving the strength of the steel plate and improving the welding performance, which helped to rationalize the use of welded structural steel and improve the safety of the building. Shipbuilding industry. However, in recent years, the requirements for the quality of steel sheets have become stricter, such as a decrease in strength. In order to meet the new requirements, based on a new concept, JFE Steel has conducted a lot of research to solve the problems related to the traditional cooling technology problems, and developed a new generation of accelerated cooling process, called super-OLAC process, and applied At JFE Steel Corporation West Japan Steel Works.

The heat transfer and boiling phenomenon that occurs when the plate is subjected to water quenching can be roughly divided into two modes, namely, nuclear boiling and film boiling. In the former boiling, the cooling water is in direct contact with the steel, and heat is transferred through the generated bubbles. In contrast, in the latter boiling, a vapor film is formed between the steel and the cooling water, and heat is transferred through the vapor film. The cooling capacity of nucleate boiling is higher than that of film boiling. At the beginning of the cooling of the plate, the surface temperature of the plate is higher, and the film boiling plays a leading role. However, as the surface temperature of the plate decreases, the vapor film becomes unstable, and the cooling water begins to partially contact the plate in a direct manner, and the boiling gradually turns to the nuclear boiling. Further, in the instantaneous boiling state, when film boiling and nuclear boiling coexist, as the cooling continues, the cooling ability is improved. With conventional cooling methods, such as spray cooling and laminar cooling, if the cooling water flow is increased to enhance cooling, the cooling is rapidly converted to instantaneous boiling, which is a mixture of nuclear boiling and film boiling. Therefore, the cooling becomes unstable, and as the cooling process continues, the temperature deviation increases, resulting in unstable plate quality.

To solve this problem, JFE Steel studied the cooling method to avoid transient boiling and simultaneous nucleate boiling on the entire surface of the plate at the beginning of cooling. Based on the study of the side cooling on the medium-thick plate, the nozzle is placed as close as possible to the plate to allow the cooling water to flow in one direction, that is, in the direction in which the plate is moved, and the cooling on the lower side of the plate is utilized. The nozzles densely arranged in the water tank are spray-cooled, that is, the water flow is taken to cool the plate. This cooling method achieves nuclear boiling with high cooling capacity on both sides of the plate. For cooling with a plate thickness of 30 mm or more, this method achieves a very high cooling rate, which is equivalent to the theoretical limit of the cooling rate.

This cooling method is 2-5 times faster than conventional accelerated cooling methods. In addition, the surface temperature distribution of the plate is very uniform after super-online accelerated cooling.

In the five years after the super-accelerated cooling equipment was put into production, more than 3 million tons of plate were processed. In May 2003, No. 2 super-accelerated cooling equipment was put into operation at the plate mill of JFE Steel's West Japan Steel Plant, and the third plant was put into operation at the plate mill of JFE Steel's East Japan Steel Plant in July 2004. . At this point, all three of JFE Steel's plate mills are equipped with accelerated cooling equipment.

Second, the new online heat treatment process - "HOP"

Up to now, the heat treatment of quenched and tempered plate has been treated off-line using a heat treatment device separate from the mill. In order to improve the efficiency of this off-line heat treatment, JFE Steel installed and commissioned the so-called HOP heat treatment process equipment at its Fukuyama Plant in the West Japan Steel Plant.

JFE Steel previously developed induction heating equipment for 2m wide roughing billets and applied it to the finishing mills of hot rolling mills. However, in order to heat medium and heavy plates up to 4.52 m wide, a large-scale new induction heating device must be developed. The device consisting of newly developed multi-frequency high-frequency power supplies runs synchronously. The application of this technology is a breakthrough, and the induction heating of medium and heavy plates is realized for the first time in the world.

The newly developed HOP is an induction heating method in which the induced current generated by the electromagnetic coil is heated by heat generated by the medium plate. From the viewpoint of heating efficiency and equipment simplification, a spiral tube type electromagnetic coil can be used. Although heat is generated inside the plate, the heat generated can be strictly controlled by controlling the input power. The heat generated by induction heating is converted into a heat flux equivalent to a heat flux value of 105-107 W/m 2 when the gas is heated, and this value is approximately 100 times higher than that of gas heating, so that heating with a large energy density can be achieved.

Immediately after the HOP device is installed in the hot straightening machine, this arrangement can improve the heating efficiency by effectively utilizing the sensible heat of the plate after super-on-line accelerated cooling. Therefore, the HOP is designed as a comprehensive heating process equipment with an inductor mounted closer to the hot straightener.

The HOP process equipment has the following two characteristics:

(1) For rolling, the simultaneous on-line heat treatment rolling-accelerated cooling-heat treatment complete online process can be realized to achieve large-scale production, which can meet the extremely short delivery schedule.

(2) The microstructure of the new plate can be controlled. The combination of HOP and super-online accelerated cooling allows free control of phase transition and control of carbon and nitrogen precipitation.

Third, the multi-purpose plate "Easyfab"

Especially in the field of shipbuilding, construction and bridge building, plate is used as an assembly after being cut into various shapes and sizes. However, the requirements for its ease of use have recently become more stringent. As a result, JFE Steel has produced a commercial plate that has good processability. Utilizing the controlled cooling characteristics of super-online accelerated cooling, the "Easyfab" plate is a material with no deformation shear, efficient assembly and good processability, and a long fatigue life.

1. Using super-online accelerated cooling process equipment to control residual stress technology

The residual stress in the plate is generally due to the difference in temperature distribution of the plate at the end of rolling. When the plate having a certain temperature distribution is cooled to room temperature, uneven cold shrinkage occurs due to the difference in position. This uneven cold shrinkage creates residual stresses. With the conventional accelerated cooling technique, the temperature difference that appears immediately after the cooling is stopped is very large, causing a large stress difference, whether in the middle plate or between the plates. Therefore, there is also a variation in deformation during the shearing process. When using the accelerated cooling technology with good cooling uniformity, ie super-online accelerated cooling technology, the plate has a uniform temperature distribution immediately after the cooling stops, reducing the residual stress of the TMCP plate to the general rolling. The same level of plate (no water cooling).

2. Development of cold straighteners with new functions and ultra-low residual stress plates

Generally, in the so-called straightening process, the straightness of the plate is corrected by a cold straightening machine (C/L). By using the C/L function to give a uniform, large strain over the full width of the plate, together with uniform cooling with super-online accelerated cooling, a plate with very low residual stress can be produced. As the bending strain at C/L increases, the residual stress after straightening decreases. In addition, ultra-low residuals can be obtained with a small C/L bending strain with a super-online accelerated cooling plate with a lower residual stress before the C/L compared to a conventional accelerated-cooled plate. Stress area. In October 2003, JFE Steel added new features to C/L at its medium and heavy plate mill in West Japan Steel, with the aim of expanding the straightening capacity and producing ultra-low residual stress plates.

(1) Vertical bending compensation using hydraulic dynamic control;

(2) Horizontal bending compensation using wedge control.

The new function of C/L adds a large and uniform bending strain to the width of the plate. For the wide and medium plate, the straightening of the plate with a maximum width of 5350mm establishes a uniform and large reduction. Straightening technology.

As described above, it is possible to produce a plate having extremely low residual stress by utilizing a super-online accelerated cooling technique with uniform cooling capability, and using a very effective C/L with a new function.

Fourth, the use of innovative processes to produce new products

1. New steel plate for shipbuilding

At present, the development trend of the shipbuilding industry is to build ships of larger size and higher load capacity. Therefore, the shipbuilding industry is increasingly using high-strength ship plates and requires excessive heat input during the welding process. Since this requirement causes coarsening of the grain structure of the heat affected zone of the weld, it is a problem to ensure low temperature toughness. In order to meet the new demands of shipbuilding, JFE Steel uses a super-online accelerated cooling technology with high cooling rate and uniform cooling capacity to produce large-size, high-strength medium-thickness with the same carbon equivalent (Ceq) as conventional plate. board.

2. Steel for construction

High-strength plate can be used as a steel structural material for high-rise buildings in the city. On the other hand, from the viewpoint of fracture damage, the demand for high-performance steel materials for building steel structures having low yield ratio, high toughness, and good welding ability is increased. Recently, for steel materials used for construction steel piles, the low temperature toughness of the heat affected zone is increased when there is a large heat input welding. To meet these requirements, JFE Steel developed a lower yield point value – 385 N/mm2 steel. As a high-strength steel with excellent economics, shock resistance and weldability, which is produced by the thermo-mechanical control process (TMCP) with super-online accelerated cooling technology, it has been recognized by the Japanese Department of Land and the Ministry of Transport. . In addition, JFE Steel has developed and commercialized medium and heavy plates with high heat-affected zone toughness and tensile strengths from 490 N/mm2 to 590 N/mm2 in the case of large thermal energy input welding.

3. Steel plate for bridge construction

Because bridges are a very important part of social infrastructure, high-quality, advanced manufacturing and assembly techniques are needed. In recent years, with the increasing number of large-scale construction and assembly and the demand for efficient assembly, the demand for high-performance steel sheets with high strength, high toughness and combined with weldability and economy has been increasing. To this end, JFE Steel develops and commercializes plates with the best balance of strength and toughness by maximizing the use of super-online accelerated cooling technology and by controlling the hardenability of alloying elements. This technology also introduces the production of ultra-low carbon bainite high-strength steel with a carbon content as low as 0.02%, achieving the production of the new standard BHS500(W) and 700W steel. The weld hardening drops sharply while achieving higher strength.

4. Steel plates for construction machinery and industrial machinery

The representative type JFE-HITEN780LE of high-strength steel for construction machinery and industrial machinery was specially developed by JFE Steel Co., Ltd., and its purpose is to reduce the weight of steel and use it for various mechanical parts. By using super-online accelerated cooling technology and HOP technology, good low temperature toughness can be obtained in a low temperature region of 40 °C.

In wear-resistant steels with special requirements for wear resistance, bending formability and impact resistance, the relevant requirements are getting higher and higher. JFE Steel has developed a new wear-resistant steel 360LE, which has a good temperature at 40 °C. Low temperature toughness with high hardness and ductility. The commercial production of such wear-resistant steel is achieved by high-speed cooling and uniform cooling of the super-online accelerated cooling technology.
Both of the newly developed steels mentioned above ensure a Ceq of 0.40 or less, so that the residual heat temperature can be lowered by 25-50 ° C compared to conventional steel.

5. High-strength steel plate for pressure vessels

Various medium and heavy plates used in the energy industry are widely used in energy storage equipment, chemical equipment and power station equipment. In recent years, the equipment used has a larger specification, and the operation and working conditions are more demanding, so the material performance requirements are more stringent to achieve higher welding efficiency, in order to reduce construction costs. These requirements include improved weldability and high reliability. To meet this type of requirements, JFE Steel has developed a high-performance 610N/mm2 high-strength steel plate that reduces residual heat and weld hardness through the use of advanced material design and innovative manufacturing techniques.

The steel plate for the large-size oil storage tank side plate is welded by high-efficiency and high-heat input welding method to 610N/mm2 high-strength steel plate, and the high-toughness 610N/mm2 high-strength steel plate can be used at lower temperature (50 °C). Advanced plate manufacturing technology is expected to meet a variety of future needs.

6. Steel plates used in pipelines have made it possible to develop oil and gas fields in the Arctic and deep sea by reducing oil and gas drilling cost technology and long-distance transportation technology. Therefore, the future trend is to transport oil and gas over long distance pipelines, and liquid energy transportation tools are more diversified. Pipeline steel requirements include high strength, good low temperature toughness and weldability. In addition, because liquid energy contains H2S, pipeline steels are required to have hydrogen-induced cracking and sulfide stress corrosion resistance. In addition, large deformations are expected in the pipeline, such as large deformation in the frozen soil, and therefore high deformation properties are required.

JFE Steel continues to develop pipeline steels that meet these stringent performance requirements by applying super-online accelerated cooling technology. Now the company can commercialize the world's strongest pipeline steel CSA grade 690 (equivalent to X100 grade pipeline steel). .

JFE Steel's new accelerated cooling technology, super-online accelerated cooling technology and in-line heat treatment technology, uses the world's first and largest induction heating method to heat plate. The use of these technologies allows them to produce high performance plates that meet a variety of processing and performance requirements.

PH Bar Series

Phlizon specialize in LED Grow Lights for for various fields such as medical, government, military, commercial, and agriculture.More than 10 years experience research and development team focus on Grow Light .Many gained the National Patents,all products passed FCC and ETL certifications. We offer High quality with the most cost-effective price.

Phlizon grow bar series are the best solution for various urban farming systems., full spectrum led grow light bars for plants growing,designed specifically for use as supplemental greenhouse lighting. Each bar 80W power.4 bars,6 bars ,8 bars 10 bars ,12 bars for choice.Adjustable bar quantity to make much more convenient repair and replacement in the future.Safety FCC ETL Certified and IP54 Rated.Passive cooling,extrusion pure aluminum can 100% ensure heat dissipation. Plants will grow better under the Full Spectrum LED Grow Lights, as well their yield. will increase hugely.

With a set of grow light bar, you can grow many plants indoors, including houseplants, orchids, and even some fruit and vegetable crops. Grow lights are ideal for seed starting because they help ensure stocky, green seedlings. A wintertime harvest of herbs and salad greens can also be grown under lights. By learning how plants use light and about the fixture options, you can select an indoor grow lights system that is right for the plants growing

Features:

High power brand Samsung 5630 led with high par vaule
Full Spectrum Grow Light mimics natural sunlight for different period of growth
Customizable spectrum,any spectrum can be OEM/ODM,at any stage of growth accordingly
APP WIFI to make operation.Standard without dimming,dimming with different PPFD
Aluminum material and heat-dissipation design
Passive cooling,no fans,no noise
Energy saving,enviromental friendly
Adjustable bar quantity to make much more convenient repair and replacement
3-5 years Warranty

Applications
Hydroponics,Horticulture,Agriculture and Greenhouse
Locations:Farm,Exhibition,Garden,Home,Urban,Bonsai,and University Lab
Growth of Fruits,Vegetables,Flowers and so on

Seeding,Rooting,Breeding,Flowering and Fruiting period

Dimmable Led Grow Bars,640W Led Grow Light,Medical Flowers Grow Bars,Led Grow Light 8 Bars

Shenzhen Phlizon Technology Co.,Ltd. , https://www.szledaquariumlighting.com