When producing stainless steel strips, if the descaling operation is not thorough, the iron oxide scale should be pressed into the stainless steel strips during rolling and straightening. After shot blasting, flaky rules or strips will appear on the surface of the stainless steel strips. Irregular defects are called water ripples. Experiments have proven that the main reasons for the formation of water ripple defects are that the iron oxide scale has not been removed cleanly, the high-pressure water nozzle is not well connected, the hardness of the roll is low, and the pressure of the pre-straightener is too high.

In view of the water-corrugated defect of stainless steel, the corresponding control measures mainly include reducing the heating temperature of the slab, optimizing the phosphorus removal process, using high-hardness rolls, and controlling the pre-straightening pressure. Let’s introduce them separately below.

Reduce stainless steel strip heating temperature

Lowering the heating temperature of the stainless steel strip refers to reducing the temperature of the steel coming out of the heating furnace from the previous 1190 ℃ to 1160 ℃. This measure can reduce the occurrence of water ripple defects to a certain extent, and can also reduce the severity of this defect. degree.

Optimizing the phosphorus removal process for stainless steel strips

The stainless steel strip rolled from the back of the machine to the front of the machine can be descaled by using the pre-machine descaling system, which can also reduce the probability of strip-like water ripples forming within a certain range. The descaling system can also be modified and a post-machine descaling system can be added to further eliminate the formation of striped water ripple defects.

Using high hardness roller stainless steel belt

When using high-chromium iron rollers, the surface hardness of the rollers is about 75 HL on the Leeb scale, which is 10 HL higher than the original high-nickel-chromium rollers. Observe the situation after use of the rollers. After removal from the machine, the surface of the rollers is smooth and clean, covered with a dense layer of Oxide film, the surface of rolled stainless steel strip is smooth, and the probability of formation of water ripple defects will also be greatly reduced.

Controlling pre-straightening pressure

After continuous understanding of the surface conditions of stainless steel strips after straightening under different pressures, the probability of water ripple defects on the surface of stainless steel strips straightened with 600 tons of pre-straightening pressure is very high, and if the straightening pressure of the pre-straightening machine is controlled at a low Below 300 tons, the probability of water ripple defects will be reduced, and the severity of the defects will be lower.

Therefore, in summary, through the above measures, the possibility of forming water-corrugated defects in stainless steel can be significantly reduced, the surface quality of the stainless steel strip can be enhanced, and the processing requirements can be better met.