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New Products
2021-05-23
Steel delivery status: hot rolling, cold rolling, normalizing, annealing, high temperature tempering, solution treatment
Serial number | Name | Description |
l | Hot rolled condition | After the hot rolling or forging, the steel is no longer specially heat treated, and it is delivered directly after cooling, which is called hot rolling or hot forging. The termination temperature of hot rolling (forging) is generally 800-900 ° C, and then generally in the air. Naturally cooled, the hot rolled (forged) state is equivalent to normalizing. The difference is because the hot rolling (forging) termination temperature is high and low, unlike the normalizing heating temperature control is strict, so the steel structure and performance fluctuations are larger than the normalizing. At present, many steel companies adopt controlled rolling. Since the final rolling temperature control is very strict and forced cooling measures are taken after the final rolling, the grain of the steel is refined, and the delivered steel has a high comprehensive mechanical property. This is the reason why the non-twist-controlled cold-rolled wire rod is superior to the ordinary hot-rolled wire rod. The steel that is delivered in the hot-rolled (forged) state has a certain corrosion resistance due to the surface covered with a scale of iron oxide, and is stored and transported. The requirements are not as strict as the steel delivered in the cold-rolled (rolled) state. Large and medium-sized steel and medium-thick steel plates can be stored in the open storage yard or after the cover. |
2 | Cold drawing status | A steel that has been cold-drawn by cold drawing, cold rolling, or the like, and is directly delivered without any heat treatment is called a cold drawn or cold rolled state. Compared with the hot-rolled (rolled) state, the steel in the cold-drawn (rolled) state has high dimensional accuracy, good surface quality, low surface roughness, and high mechanical properties, and is delivered in a cold-drawn (rolled) state. The surface is free of scale covering, and there is a large internal stress, which is highly susceptible to corrosion or rust. Therefore, the steel in the cold drawn (rolled) state has strict requirements for packaging, storage and transportation, and generally needs to be stored in the warehouse. And should pay attention to the temperature and humidity control in the warehouse |
3 | Normalizing state | The steel is subjected to normalizing heat treatment before leaving the factory, and this delivery state is called a normalizing state. Due to the normalizing heating temperature (the sub-eutectoid steel is Ac3+30～50°C, the hypereutectoid steel is Accm+30～50°C), the temperature control is stricter than the hot rolling end temperature, so the microstructure and properties of the steel are uniform. Compared with the annealed steel, the normalized cooling rate is faster, the number of pearlite in the steel structure increases, the pearlite layer and the grain of the steel are refined, so that it has higher comprehensive mechanical properties and is beneficial to improvement. The Wei's structure of the mild steel and the cementite network of the hypereutectoid steel can be prepared for further heat treatment of the finished product. Carbon steel and consolidated steel are often delivered in a normalized state. Certain low-alloy high-strength steels such as 14MnMoVBRE and 14CrMnMoVB steels are also required to be delivered in a normalized state in order to obtain a bainite structure. |
4 | Annealed state | The steel is annealed and heat treated before leaving the factory, and this delivery state is called annealed state. The purpose of annealing is mainly to eliminate and improve the structural defects and internal stress left in the previous process, and to prepare for the organization and performance of the subsequent process, alloy structural steel, guaranteed hardenable structural steel, cold heading steel, bearing Steel, tool steel, steam turbine blade steel, iron wire type stainless steel heat-resistant steel |
5 | High temperature tempering status | The steel is heat treated by high temperature tempering before leaving the factory. This delivery state is called high temperature tempering. The high tempering temperature of high temperature tempering is beneficial to completely eliminate internal stress and improve plasticity and toughness. Carbon structure, alloy steel and steel structure ensuring hardenability can be delivered in high temperature tempering state. Some martensitic high-strength stainless steel "target=_blank> stainless steel, high-speed tool steel and high-strength alloy steel, due to high hardenability and strengthening of alloying elements, often after quenching (or tempering) High temperature tempering, so that the carbides in the steel are properly aggregated, and the tempered sorbite structure (similar to the spheroidized annealed structure) with coarse carbide particles is obtained. Therefore, the steel in the delivery state has good cutting performance. |
6 | Solution treatment status | The steel is treated by solution treatment before leaving the factory. This delivery state is called solid solution treatment. This state is mainly applicable to the treatment of austenitic stainless steel "target=_blank> stainless steel before leaving the factory. Through solid solution treatment, a single-phase austenite structure is obtained to improve the toughness and plasticity of the steel for further cold working (cold rolling) Or cold drawing) to create conditions, but also to prepare for further precipitation hardening |
Annealed steel bar is produced by annealing which is one kind of heat treatment to get proper hardness for machining. Our advantages and more services of annealed steel bar includes:
1) Wide range of diameters from 10mm to 300mm
2) Customized Length from 100mm to 12000mm
3) Good surface roughness: 0.4um to 1.5um
4) Good straightness: 0.5mm/m to 2mm/m
5) Good roundness: 80% of diameter tolerance
6) Diameter tolerance: -0.02mm to -0.06mm/h9, h10, h11
7) Matched further processing: Grinding, polishing, straightening
8) Anti-rusty package
9) Full sets of testing equipment: Surface, Dimenstion. Mechanical properties testing
10) Fast delivery time
