First, the characteristics of Q355C hot-rolled steel plate
(a) Chemical composition and performance: Q355C is a low-alloy high-strength structural steel, and its chemical composition includes carbon, silicon, manganese, and other elements. The moderate carbon content ensures the strength of the steel, and the presence of manganese improves the toughness and hardenability of the steel. The yield strength of the Q355C steel plate is not less than 355MPa. It has good comprehensive mechanical properties and can withstand large loads. It is suitable for many fields such as construction and machinery manufacturing.
(b) Influence of hot rolling process: Hot-rolled steel plate is made by heating the billet and then rolling it. For Q355C hot-rolled steel plate, the hot rolling process makes it have good plasticity and toughness. During the hot rolling process, the internal structure of the steel is refined and homogenized, which reduces the internal stress and improves the quality of the steel plate. In addition, the dimensional accuracy of the hot-rolled steel plate is relatively high, and the surface quality is good, which provides favorable conditions for subsequent punching and cutting processing.
Second, drilling processing of Q355C hot-rolled steel plate
1. Drilling processing of Q355C hot-rolled steel plate:
(a) Tool selection for drilling processing of Q355C hot-rolled steel plate: Select a suitable drill bit according to the thickness of the steel plate and the size of the hole diameter. For Q355C steel plate, high-speed steel drill bits or carbide drill bits are generally used. If the hole diameter is small (for example, less than 10mm) and the steel plate thickness is not large (less than 10mm), a high-speed steel drill bit can meet the requirements; if the hole diameter is large or the steel plate is thick, a carbide drill bit can provide better wear resistance and cutting efficiency.
(b) Cutting parameter setting for drilling processing of Q355C hot-rolled steel plate: When drilling, the cutting speed and feed rate should be set reasonably. The cutting speed depends on the drill bit material and the material of the steel plate. For high-speed steel drill bits, the cutting speed is generally around 10-20m/min; for carbide drill bits, the cutting speed can be appropriately increased to 20-30m/min. The feed rate is adjusted according to the hole size and steel plate thickness, generally between 0.1-0.3mm/r. At the same time, in order to prevent the drill bit from overheating and improve the drilling quality, cutting fluid, such as emulsion, is required for cooling and lubrication.
2. Punching of Q355C hot-rolled steel plate:
(a) Principle and equipment: Punching uses the relative movement between the punch and the die to cause the steel plate material to shear and deform under the pressure of the punch, thereby forming a hole. The punching equipment is mainly a punch press, and the pressure of the punch press should be selected according to the thickness of the steel plate and the hole size. For the Q355C steel plate, when the punching diameter is 10-20mm and the steel plate thickness is 5-10mm, the punch press pressure needs to be around 100-200kN.
(b) Die design and quality control: Die design is the key to punching processing. The gap between the punch and the die should be reasonably set according to the thickness and material of the steel plate. For the Q355C steel plate, the gap between the punch and the die is generally between 5% and 10% of the thickness of the steel plate. If the gap is too large, burrs and tears will appear on the edge of the punch; if the gap is too small, the wear of the punch and the die will increase, and the life of the die will be reduced. At the same time, during the punching process, attention should be paid to controlling the stroke and speed of the punch press to ensure the quality of the punching.
Third, the cutting process of Q355C hot-rolled steel plate
1. Flame cutting of Q355C hot-rolled steel plate
(a) Principle and equipment of flame cutting: Flame cutting is to melt the steel plate by a high-temperature flame generated by the combustion of a mixture of fuel gas (such as acetylene, propane, etc.) and oxygen, and then use a high-pressure oxygen flow to blow away the molten metal to achieve cutting. The equipment mainly includes cutting torches, oxygen cylinders, and gas cylinders.
(b) Parameter adjustment and quality control of flame cutting: For Q355C steel plates, the cutting speed and flame intensity should be adjusted according to the thickness of the steel plate. When the thickness of the steel plate is 10-20mm, the cutting speed is generally around 200-300mm/min, and the flame intensity should ensure that the steel plate can be fully melted. At the same time, pay attention to the vertical relationship between the cutting nozzle and the steel plate to avoid tilting the cutting surface. In addition, in order to reduce the heat-affected zone and improve the cutting quality, the cutting surface can be polished after cutting.
2. Plasma cutting of Q355C hot-rolled steel plate:
(a) Principle and equipment of plasma cutting: Plasma cutting uses a high-temperature plasma arc to melt and blow away steel plate materials. The equipment mainly includes a plasma cutting machine, an electrode, and a nozzle. The temperature of the plasma arc is extremely high, which can quickly melt the Q355C steel plate.
(b) Parameter adjustment and quality control of plasma cutting: When plasma cutting Q355C steel plates, the current, cutting speed, and gas flow rate should be adjusted according to the thickness of the steel plate. For example, when the thickness of the steel plate is 6-10mm, the current is generally around 100-150A, the cutting speed is between 100-200mm/min, and the gas flow rate is appropriately adjusted according to the equipment requirements and cutting effect. During the cutting process, pay attention to the wear of the electrode and nozzle and replace them in time to ensure the cutting quality. At the same time, prevent the occurrence of uneven cuts and slag.
3. Laser cutting of Q355C hot-rolled steel plate:
(a) Principle and equipment of laser cutting: Laser cutting uses a high-energy-density laser beam to irradiate the surface of the steel plate to melt and vaporize the material, and then blows away the melted and vaporized material through auxiliary gas. The equipment mainly includes a laser cutting machine, laser generator, and auxiliary gas system.
(b) Parameter adjustment and quality control of laser cutting: For laser cutting of the Q355C steel plate, the appropriate laser power and cutting speed should be selected according to the thickness of the steel plate. For example, when the thickness of the steel plate is less than 5mm, a laser power of 1-2kW and a cutting speed of 1-2m/min may be sufficient; when the thickness of the steel plate is 10-15mm, a laser power of 3-5kW and a cutting speed of 0.5-1m/min may be required. Auxiliary gas generally chooses nitrogen or oxygen. Nitrogen can obtain an oxidation-free cutting surface, and oxygen can increase the cutting speed but may cause oxidation of the cutting surface. The auxiliary gas pressure is generally between 0.8 and 1.5MPa. At the same time, it is necessary to ensure that the laser beam is perpendicular to the surface of the steel plate and that the steel plate is properly fixed to prevent the steel plate from moving during the cutting process and affecting the cutting quality.
Post time: Jun-18-2025