Core Tip: During the rolling process, the working surface of the rolling mill forging wears out quickly. As it is a tool that directly deforms the rolled piece, the change in roll shape will directly affect the quality of the steel plate. Therefore, it is necessary to control the roll shape of the rolling mill
During the rolling process, the working surface of roll forgings wears out rapidly. As it is a tool that directly deforms the rolled piece, the change in roll shape will directly affect the quality of the steel plate. Therefore, it is necessary to accurately control the accuracy of the rolling mill, such as the size, deformation, thermal expansion, wear, and thermal convexity of the rolling mill. The inspection of rolling mill forgings is a fundamental means of understanding the geometric shape and accuracy of rolling mills.
The inspection of rolling mill forgings mainly includes the following contents:
(1) Hardness testing, such as Shore HSD, HSC, Leeb HLD, Brinell HB, Vickers HV, and microhardness. Each rolling mill should undergo hardness testing. Take four busbars at a distance of 90 degrees along the circumference of each rolling mill roll, with approximately equal spacing between 5 test points for each busbar. Measure 5 times at each test point and calculate the average value; Take 2 busbars on the roll neck at a distance of 180 degrees in the circumferential direction, with 5 points on each busbar. Measure 5 times at each test point and calculate the average value.
(2) Strength testing, such as yield strength, tensile strength, flexural strength, and compressive strength.
(3) Plastic index testing, such as elongation and reduction in cross-sectional area.
(4) Resilience index testing, such as impact energy and fracture toughness.
(5) Microscopic structure inspection, such as metallographic structure inspection, quantitative inspection of different structures, etc.
(6) Non destructive testing, such as ultrasonic testing, dye penetrant testing, and magnetic particle testing. (Radial and Axial)
(7) Residual stress testing, such as X-ray stress testing, drilling stress testing, and magnetic stress testing.