Hardness Details: The surface Rockwell hardness of annealed plain carbon steel is generally 55+-3, and the hardness of unannealed cold-rolled hard-rolled strip steel is above 80. The thickness of cold-rolled strip and sheet is generally 0.1-3mm and the width is 100-2000mm; both are made of hot-rolled strip or steel plate. . CRS is the abbreviation of English cool rolling steel, that is, cold rolled steel. It refers to the rolling process of steel. For example, q235 ordinary carbon steel plate can be cold rolled, and 10# steel plate can also be cold rolled. Its hardness can be on the corresponding standard according to the steel used. .
Cold-rolled sheet is the abbreviation of ordinary carbon structural steel cold-rolled sheet, also known as cold-rolled sheet, commonly known as cold-rolled sheet, and sometimes mistakenly written as cold-rolled sheet. The cold plate is made of ordinary carbon structural steel hot-rolled steel strip, which is further cold-rolled into steel with a thickness of less than 4mm. . Cold rolled sheet is divided into: 1/8 hard, 1/4 hard, 1/2 hard and full hard state. There are generally two main units of hardness value: HRB (Rockwell) HV (Vickers) as follows: Quality identification symbol HRB (Rockwell) HV (Vickers) 1/8 hardness. . Pickling plate is to pickle the surface of the hot-rolled plate through dephosphorization (removal of rust, residue, etc. produced during the hot-rolling process), so as to obtain a steel plate with better performance than hot-rolling. -Rolled surface. It can be seen from its manufacturing process that its hardness is the same level of hot rolling. .
There is basically no difference in surface hardness between cold rolled and galvanized. Because the galvanized surface is only coated with a layer of zinc of a few microns to about 20 microns on the substrate. The base material is generally cold rolled and hot rolled. The hardness mainly depends on the grade of the material, and the grades are different. . Take DC01 and DC03 as examples. DC01 upper limit of yield strength 280 DC03 upper limit of yield strength 240 , dc06+ze correspond to cold-rolled sheets respectively, the numbers represent the stamping grade, the larger the number. Cold-rolled sheet is made of hot-rolled coil as raw material, rolled at room temperature lower than recrystallization temperature, and its hardness is about 150HV. Shearing machine blades are generally made of tool steel with a hardness of HRC55~58°, which can cut most of them.