Good quality and cheap imports of container board

ASME is the American Society of Mechanical Engineers (American Society of Mechanical Engineers) abbreviation. American Society of Mechanical Engineers was founded in 1880, built a branch in the world, is a great authority and influence of international academic organizations. ASME is mainly engaged in the development of mechanical engineering and related fields of science and technology, to encourage basic research, promoting academic exchanges, development and other engineering associations, to carry out standardization activities, the development of mechanical specifications and standards. It has 125,000 members, manages the world's largest technical publishing department, presided over 30 technical conferences each year, 200 professional development programs, and developed a number of industrial and manufacturing standards. The current domestic production of such containers are mainly Wuyang steel plate, in addition to this grade also produced the following grades: SA516Gr70, SA515Gr65, SA515Gr70, SA516Gr60, SA516Gr65, SA662Grc, and so on. Because this material is rather special, so the use of this material to use is the result of party specified, the overall amount will be relatively small, the steel produced, the flow into the market is relatively small, good procurement

The delivery status of the container board

Commonly used in the delivery state the following:

Quenching: heated to temperatures above the phase transition point, the rapid cooling process. Improve the hardness of the material, but lower toughness.

Normalized: heated to above the phase transition temperature, the normal cooling (in air).

Annealing: Heat to a temperature above the phase transition point, the slow cooling. Eliminate the quenching effect, eliminate stress, uniform composition.

Tempering: After hardening, and then heated to a temperature (below the quenching temperature), heat, and cooling. Uniform composition, slightly lower hardness, substantial increase in toughness.

In general: first annealing, normalizing; remove the original heat treatment effects. And then quenched, then tempered.

Specifically:

Controlled rolling is controlled rolling.

That is, adjusting the chemical composition of steel on the basis of the temperature by controlling the heating, rolling temperature and deformation system and other process parameters to control the austenite phase transition and the changes of the organizational form of the product, to refine the organization to improve the strength and toughness of purpose.

Controlled rolling and controlled rolling style is normalizing, controlled rolling temperature, rolling reduction, cooling rate, and the finishing temperature and other measures to achieve good performance of steel toughness ratio

Normalizing, also known as normalization, the workpiece is heated to above Ac3 or Accm 30 ~ 50 ℃, holding for some time, removed from the furnace in the air or water, or hair spray cooling of the metal heat treatment process. Normalizing and annealing of the difference is normalized cooling rate slightly faster than the annealing cooling rate, thus normalizing the organization even more carefully than the annealing, the mechanical properties also improved. In addition, external cooling is not occupied by the fire equipment, higher productivity, thus normalizing the production as far as possible instead of annealing.

Normalizing the main application are: ① for low carbon steel, hardness after normalizing slightly higher than the annealing, good toughness, can be used as pre-machining. ② used in carbon steel, quenched and as a substitute for the final heat treatment, induction heating can also be used as a method of surface preparation before quenching process. ③ for tool steel, bearing steel, hardened steel, etc., can reduce or eliminate the formation of carbides inhibit the mesh to get the ball annealing required good organization. ④ for steel castings, cast structure can be refined to improve the cutting performance. ⑤ for large forgings, as a final heat treatment, quenching in order to avoid cracking of the larger trend. ⑥ for ductile iron, the hardness, strength, wear resistance is improved, such as for the manufacture of automobiles, tractors, diesel engine crankshaft, connecting rod and other important parts. ⑦ hypereutectoid ball once before annealing normalizing, can eliminate the secondary cementite network, to ensure that annealing of the ball when the ball all the particles of cementite.

Annealing annealing

Heating the workpiece to a predetermined temperature, holding a certain time after the slow cooling of metal heat treatment process. The purpose of annealing is: ① improve or eliminate the steel in the casting, forging, rolling and welding process caused by the residual stress and defect and to prevent workpiece deformation and cracking. ② soften the workpiece for machining. ③ grain refinement, improvement of the organization in order to improve the mechanical properties of the workpiece. ④ for the final heat treatment (quenching and tempering) prepare the organization to prepare. Commonly used annealing process are: ① fully annealed. To refine the medium and low carbon steel by casting, forging and mechanical properties after welding of thick hot poor organization. The workpiece is heated to ferrite into austenite temperature all over 30 ~ 50 ℃, holding for some time, and then slowly cooled with the furnace, the cooling process in the transformation of austenite occurs again, the organization can make the steel thinner . ② ball annealing. To reduce the tool steel and bearing steel, high hardness after forging. The workpiece is heated to a temperature of austenitic steel begins to form more than 20 ~ 40 ℃, heat after slow cooling in the cooling process of pearlite cementite lamellae into spherical, thereby reducing the hardness. ③ isothermal annealing. To reduce some of the nickel, high chromium alloy steel of high hardness, for cutting. A faster rate of cooling is generally the first to the most unstable austenite temperature, holding an appropriate time, austenite or austenite sorbite care, hardness can be reduced. ④ recrystallization annealing. To eliminate the metal wire, sheet in the cold drawing, cold rolling process of hardening (hardness increased, decreased plasticity). Heating temperature is generally begin to form austenite steel temperatures below 50 ~ 150 ℃, the only way to eliminate the effect of hardening the metal to soften. ⑤ graphitization annealing. Used to make cast iron containing a large number of cementite into good malleable iron plasticity. Casting process operation is heated to about 950 ℃, holding a certain time after appropriate cooling, the formation of cementite decomposition group flocculent graphite. ⑥ diffusion annealing. Chemical composition of the alloy castings for uniformity, to improve its performance. Is melting does not occur in the premise, the casting is heated to temperatures as high as possible, and long insulation, diffusion of elements in the alloy to be more uniform distribution after slow cooling. ⑦ to stress annealing. Steel castings and to eliminate the stress of welded parts. For iron and steel products began to form austenite after heating at temperatures below 100 ~ 200 ℃, heat in the air after cooling, can eliminate the internal stress.

Tempering tempering; temper, also known with the fire. A metal heat treatment process. After hardening of the workpiece will be re-heated to below the critical temperature under an appropriate temperature, holding for some time in the air or water, oil, heat treatment of metal cooling medium. Or the alloy after quenching the workpiece is heated to a suitable temperature, holding for some time, and slow or rapid cooling. Quenching generally used to reduce or eliminate internal stress in the steel, or reduce its hardness and strength, ductility or toughness to improve their. According to different requirements can be low-temperature tempering, tempering temperature or high-temperature tempering. Usually with the tempering temperature, lower hardness and strength, ductility or toughness gradually increased. Steel workpiece after quenching has the following characteristics: ① been martensite, bainite, residual austenite and other imbalances (ie, unstable) organization. ② there is a big stress. ③ mechanical properties can not meet the requirements. Thus, after quenching of steel to go through the normal tempering. Tempering effect is: ① improve organizational stability, so that the workpiece does not recur in the course of organizational change, so that the workpiece geometry and performance remained stable. ② eliminate stress, to improve performance and stability of the workpiece the workpiece geometry. ③ Adjust the mechanical properties of steel to meet the requirements. Hardening or Quenching Quenching (industry, quenching reading 'zhàn' sound) hardened steel is steel is heated to the critical temperature Ac3 (sub-eutectoid steel) or Ac1 (eutectoid steel) over a certain temperature, holding time, the of all or part of austenitizing, then cooling rate greater than the critical cooling rate the following fast-cooling to the Ms (Ms or near isothermal) to martensite (or bainite) into the heat treatment process. Usually the aluminum alloy, copper alloy, titanium, glass and other materials, with a rapid cooling solution treatment or heat treatment process is called quenching. The purpose is to quenching of undercooled austenite to martensite or bainite, martensite or bainite obtained, and then with a different temperature tempering, to significantly increase the strength of steel, hardness, wear resistance, fatigue strength and toughness to meet a variety of mechanical parts and tools for different requirements. You can also meet some of the special steels quenched ferromagnetic, corrosion resistance and other special physical and chemical properties. Hardened steel can enhance the root cause of the phase transition, that is austenite by the martensite phase transformation to become (or bainite). Quenching quenching and tempering: the general habit of quenching and tempering heat treatment as a combination of quenching. Quenching is widely used in a variety of important structural parts, especially those who work in the alternating load the rod, bolts, gears and shafts, etc. Quenched and tempered sorbite organization obtained its mechanical properties than the same hardness normalizing sorbite organization is superior. It depends on the hardness and high temperature tempering steel tempering temperature and the stability and size of the workpiece cross-section, usually between the HB200-350