one、definition
Cold rolled steel plate refers to the steel plate produced through the cold rolling process。Cold rolling is a process of rolling under conditions lower than the recrystallization temperature of the metal。It is based on hot-rolled steel plates，After acid washing to remove surface oxide skin，Made by cold rolling processing again。
two、Production process
raw material preparation
The raw materials for cold-rolled steel plates are usually hot-rolled steel plates or steel coils。Hot rolled steel plates are heated in a heating furnace，Rolled into a certain thickness of steel plate through rough rolling and precision rolling processes。Before cold rolling，Need to inspect hot-rolled steel plates，Ensure its surface quality、Dimensional accuracy meets the requirements。
acid pickling
A layer of oxide scale will form on the surface of hot-rolled steel plate，This will affect the quality of cold rolling。Acid washing is the use of acid solution（Like sulfuric acid、Hydrochloric acid, etc）Chemical reaction with oxidized skin，Remove the oxide skin。Strictly control the concentration of the acid solution during the pickling process、Temperature and pickling time，To ensure that the oxide scale can be thoroughly removed，Simultaneously avoiding excessive corrosion of the steel plate substrate。
cold rolling
The pickled steel plate enters the cold rolling mill。Cold rolling mills usually have multiple rolling processes，Each rolling process gradually reduces the thickness of the steel plate，Simultaneously improve the surface quality and dimensional accuracy of steel plates。During the cold rolling process，Steel plates will experience significant compressive stress，Therefore, it is necessary to regularly grind the rolling mill rolls，To ensure the surface quality of the rolling mill，To ensure the surface quality of cold-rolled steel plates。
annealing
Cold rolled steel plates will undergo work hardening，Hardness increase，Reduced resilience。Annealing is the process of heating cold-rolled steel plates to a certain temperature（Usually below the recrystallization temperature），The process of holding for a period of time and then slowly cooling down。Annealing can eliminate work hardening，Restore the toughness and plasticity of steel plates，At the same time, it can also improve the microstructure of steel plates，Improve its performance。
Flattening and finishing
After annealing, the steel plate may have some surface defects or shape defects，Like waves、Piaoque, etc。The leveling process is a slight rolling of steel plates by a leveling machine，Eliminate these defects，Make the surface of the steel plate smoother and more even。The finishing process also includes cutting the steel plate、Straightening and other operations，Make it meet the size and shape requirements of the user。
three、Performance characteristics
High dimensional accuracy
Cold rolling process can accurately control the thickness and width of steel plates，Higher dimensional accuracy than hot-rolled steel plates。for example，The thickness tolerance of cold-rolled steel plates can be controlled within a very small range，Suitable for occasions with high requirements for dimensional accuracy，Like automobile manufacturing、Production of household appliance casings, etc。
Good surface quality
Cold rolled steel plates undergo acid pickling and cold rolling，smooth、level，No defects such as oxide skin。The surface roughness can be adjusted according to user needs，Can produce mirror like bright surface steel plates，It is also possible to produce surfaces with a certain roughness，To meet different painting requirements、Processing and other requirements。
Excellent mechanical performance
The strength and hardness of cold-rolled steel plates are relatively high，This is due to the work hardening effect generated during the cold rolling process。After annealing treatment，Its resilience can also be guaranteed。for example，Cold rolled high-strength steel plates can be used to manufacture automotive body structural components, etc，Can meet the strength requirements，It also has good formability。
four、classification
Function
Cold rolled steel plates for construction：Used for architectural decoration、Roof covering, etc。This type of steel plate usually requires good corrosion resistance and a certain strength。for example，Color coated cold-rolled steel plate，By coating a layer of colored coating on the surface of cold-rolled steel plate，Not only beautiful, but also，It can also improve its corrosion resistance performance。
Cold rolled steel plates for automobiles：It is an important material for automobile manufacturing，Including the exterior panel of the vehicle body、INNER PANEL、Structural components, etc。Cold rolled steel plates for automobiles require high strength、Good formability and welding performance。for example，High strength cold-rolled dual phase steel can be used for automotive body structural components，Can improve safety while reducing the weight of the car。
Cold rolled steel plate for household appliances：Used for manufacturing refrigerators、washing machine、The casing of air conditioners and other household appliances。This type of steel plate requires high surface quality，Easy to apply and process。for example，Cold rolled steel plates that have undergone surface treatment can improve the aesthetics and durability of household appliance casings。
Classified by surface treatment
Galvanized cold-rolled steel sheet：Improving the corrosion resistance of cold-rolled steel plates by coating them with a layer of zinc on the surface。There are two types of galvanizing methods: hot-dip galvanizing and electroplating galvanizing。The zinc layer of hot-dip galvanizing is thicker，Better corrosion resistance，Suitable for harsh environments；The zinc layer of electroplated zinc is relatively thin，The surface is smoother，Suitable for occasions with high requirements for surface quality。
Tin plated cold-rolled steel plate：Mainly used in fields such as canned food packaging。Tin plating can prevent steel plates from rusting，At the same time, it has a certain protective effect on food。
Coated cold-rolled steel plate：Apply a layer of organic coating on the surface of cold-rolled steel plate，Like polyester、Epoxy resin, etc。Coatings can provide good decorative properties、Corrosion resistance and wear resistance。for example，Coated cold-rolled steel sheet for exterior walls of buildings，Capable of resisting erosion from the external environment，Simultaneously possessing a beautiful appearance。
five、application area
Automobile industry
Cold rolled steel plate is one of the main materials used in automobile manufacturing。Most of the components of a car body，Like a car door、car roof、Engine hood, etc，They are all stamped from cold-rolled steel plates。The use of high-strength cold-rolled steel plates can reduce the weight of automobiles，Improve fuel economy，At the same time, it can also ensure the safety of the car。
Home appliance industry
fridge、washing machine、The shells of air conditioners and other household appliances are mostly made of cold-rolled steel plates。The excellent surface quality and formability of cold-rolled steel plates enable them to meet the complex shape requirements of household appliance casings，And its aesthetics and durability can be improved through surface treatment。
construction industry
Cold rolled steel plates can be used for building roofs、wall decoration、Steel structures, etc。Color coated cold-rolled steel plates are widely used in architectural decoration，It has rich colors，Can match the architectural style，Simultaneously possessing excellent weather resistance。
Mechanical manufacturing industry
Cold rolled steel plates can be used to manufacture various mechanical components，Like gears、Axis, etc。Its excellent mechanical performance and dimensional accuracy can meet the precision requirements of mechanical manufacturing。