Technical Article

Testing of roll

During the rolling process of the roll, its working surface wears quickly. Because it is a tool that directly deforms the rolled product, the change of the roll shape will directly affect the quality of the steel plate. Therefore, the accuracy of the roll, such as the size, deformation, thermal expansion, wear and thermal convexity of the roll, must be accurately controlled. Roll inspection is the basic means to understand the geometry of the roll and its accuracy.

Roll inspection mainly includes the following:

(1) Hardness testing, such as Shore HSD, HSC, Leeb HLD, Brinell HB, Vickers HV and microhardness. Rolls should be tested for hardness one by one. Take four busbars at a distance of 90 degrees along the circumference of each roll body, and take 5 test points for each busbar with approximately equal spacing. Each test point is measured 5 times and the average value is calculated; the distance between the roll necks in the circumferential direction is 180 Take 2 bus bars, take 5 points on each bus bar, measure each test point 5 times, and find the average value.

(2) Strength inspection, such as yield strength, tensile strength, flexural strength, and compressive strength.

(3) Inspection of plastic index, such as elongation and reduction of area.

(4) Inspection of toughness indexes, such as impact energy and fracture toughness.

(5) Microstructure inspection, such as metallographic organization inspection, quantitative inspection of different tissues, etc.

(6) Non-destructive testing, such as ultrasonic testing, color penetrating testing, and magnetic particle testing. (Radial and axial)

(7) Residual stress detection, such as X-ray stress detection, borehole stress detection, and magnetic stress detection.