Rough Turned 1.6582 Steel Shaft

1 Flaw detection
Conduct on-site dye penetrant inspection on the surface of the support roller body and neck to detect whether there are cracks on the surface; Conduct ultrasonic nondestructive testing on the inside of the support roller to detect whether there are cracks, inclusions, and other defects inside, as well as the depth of the cracks, inclusions, and determine whether it can be repaired by surfacing welding and the amount of turning processing for the roller.
2 Roll surface turning
According to the process requirements, cut a hardened layer of no less than 50mm on one side, and process it into a welding groove shape, ensuring the design thickness of the surfacing layer. Conduct all-round flaw detection on the processed roller surface and welding groove to confirm that there are no defects on the roller. If a local defect is still found, cut the defective part in the circumferential direction until there is no defect.
3 Roll surface preheating
The roller enters a special heating furnace for preheating, with a preheating temperature of 400~500 ℃; The furnace temperature shall be controlled by a computer and the temperature shall rise slowly (30~40 ℃/h); During the heating process, the support roller should rotate slowly and continuously to ensure uniform heating temperature. After the roller reaches the set preheating temperature, it should be kept warm for a certain time to ensure that the roller core temperature reaches the required preheating temperature.
4 Roller surface surfacing
The surfacing layer is divided into three layers: the base layer, the transition layer, and the working layer.
(1) Underlayer: Use low-carbon alloy welding wires with good welding performance and high strength. It is mainly used to make it have good compatibility with the substrate, crack resistance, and high strength.
(2) Transition layer: Due to the low hardness of the base layer, it is necessary to stack 3 layers of transition layers with hardness and strength between the base layer and the working layer to serve as a connecting link.
(3) Working layer: Select welding wires with low carbon content and high alloy content to improve the strength and wear resistance of the working layer. The hardness of the working layer is HSD50-60. Due to the relatively high alkalinity of cooling water in Anyang Iron and Steel Group, the selected working layer material should also have a certain degree of alkali resistance.
The entire surfacing process is conducted in a preheating furnace, with heat preservation and surfacing at the same time. The purpose is not only to restore the size of the roller body, but also to ensure the mechanical properties of the surfacing layer.
5 Roll surface tempering
During the surfacing process, multiple tempering treatments are conducted according to the tempering process requirements to eliminate welding stress, expand hydrogen treatment, improve the metallographic structure of the surfacing layer, and adjust the hardness of the surfacing layer.
6 Roll surface turning
After the surfacing layer reaches the required size, it is mounted and leveled, and the roll body size is Φ L801mm, with a grinding allowance of 0.5mm on one side.
7 Roller surface inspection
Perform non-destructive testing (surface coloring, ultrasonic testing) on the roll body, and measure the hardness and diameter of the roll.

Characteristics:

(1) High compressive strength and good rigidity, sufficient to withstand high rolling forces and peak loads;
(2) Good toughness to avoid roller breakage, barrel cracks, and surface peeling;
(3) The working layer of the roller body has good wear resistance and fatigue resistance to reduce roller consumption;
(4) The working layer of the roller body has uniform structure and hardness, making the entire roller surface have uniform wear resistance;
(5) It has good corrosion resistance to resist corrosion from high temperatures and lubricating or cooling media during hot rolling.