The difference between cold rolling, hard rolling, cold forming, and pickling of steel pipes and the difference in application

First, the definition of steel pipe processing
When analyzing the varieties, the first thing to clarify is the definition of these products. These common names usually refer to low-carbon steel coils:
Pickling: usually refers to the product of hot-rolled steel coils after the pickling unit removes the surface oxide scale.
Hard rolling: usually refers to the product of hot-rolled steel coils after pickling, and then thinned by cold rolling mills, but not annealed.
Cold rolling: usually refers to the product of hard-rolled coils after complete or incomplete annealing.
Cold forming: usually refers to hot-rolled pickled thin strip steel produced by ESP continuous casting and rolling process.
Pickling, hard rolling, and cold rolling products are products of different stages in the traditional production process. Pickling is the product of hot rolling to remove oxide scale, and hard rolling is the product before cold rolling annealing. However, cold forming is a new product produced by the ESP production line (combining the two processes of continuous casting and hot rolling into one unit). This process has the two characteristics of low cost and thin hot rolling thickness, which have been the main direction of many domestic steel mills in recent years.

Second, the difference in comprehensive performance and application
The base material of pickled coils has not changed compared with hot rolling and is often used in occasions where hot rolling has higher surface quality requirements. Common grades SPHC, commonly known as "pickled C material" in the industry.
The price of hard rolled coils is not cheap, and the formability and surface quality are not good, so they are usually only used in some specific industries with thin specifications and low-performance requirements, such as umbrella ribs, or factory lockers. Common grades CDCM-SPCC, commonly known as "cold-hardened C material" in the industry.
Cold-rolled coils have good comprehensive performance, but the disadvantage is that they are the most expensive (most processes and highest costs). Common grades SPCC, commonly known as "cold-rolled C material" in the industry.
The forming performance of cold-formed coils is much better than that of hard-rolled coils, but not as good as that of cold-rolled coils (mainly affected by heat treatment capacity and large flat work hardening after pickling). The outstanding advantage is that the cost is very low, especially in the thickness range of 1.0~2.0, which is used to replace cold-rolled products with low forming requirements (such as rolling, bending, etc.).