TWI582402B - Steel coil rolling defect detection method - Google Patents

Description

Method for detecting rolling coil rolling defects

The invention relates to a method for detecting rolling defects of steel coils, and in particular to a method for detecting pre-rust removal of steel coils using a glow discharge device.

Nearly 80% of the influencing factors affecting the quality and yield of hot-rolled coils come from the production rolling process, and the rolling defects caused by improper control of oxidized scale are the largest. Common defects on the surface of coils are strip, sand, red rust, spindle, sheet and so on. The visible parts of these defects are present on the surface, but some must be seen until the steel coil is pickled, ie the defects are present inside and cannot be visually inspected.

The surface defect inspection of hot-rolled black-skin steel coils is mainly achieved by manual visual or image recognition, but internal defects existing between the scale and the substrate cannot be detected. To know or detect the presence of defects between the surface and the substrate interface prior to pickling of the hot rolled black-skin steel coil, one of the prior art techniques can use a mechanical grinding device to parallelly grind the surface for layer-by-layer removal until Arrived at a specific level containing the characteristic structure, but the disadvantage is that the pressure applied by the manual grinding and the mechanical destructive force of the sandpaper are too good, so it is not easy to grind the position of the specific point (layer). grip. The second technique can be fixed-point etching by using focused ion beam technology. Although the ion beam etching can accurately make a cross-section or parallel sample, the preparation area is often small (micrometer μm) and the time required. Longer, less suitable for demand.

Accordingly, it is an aspect of the present invention to provide a method of detecting a steel coil prior to rust removal using a glow discharge device.

According to the above aspect of the invention, there is provided a method for detecting a rolling defect of a steel coil, which comprises the following steps. A flat test piece is cut on a steel coil, and its length and width are each 4 to 7 cm. The flat test piece is placed in a glow discharge device, and the flat test piece is connected to the negative electrode, and argon gas is introduced to cause the dissociated argon ion to accelerate against the surface of the test piece after being accelerated by the voltage. The parameter conditions for adjusting the glow discharge device are pressure 600~800Pa, power 20~40W, and argon ion impact time 30~300 seconds to remove the scale of the test piece. The flat test piece was taken out for detection analysis.

According to an embodiment of the invention, the pressure of the glow discharge device is set to 650 Pa.

According to an embodiment of the invention, the power of the glow discharge device is set to 30W.

According to an embodiment of the invention, the argon ion ion impact time of the glow discharge device is set to 150 seconds.

According to an embodiment of the present invention, the flattened test piece has a length and a width of 4 cm each.

The method for detecting the rolling defect of the steel coil according to the present invention is used The technology of the glow discharge device removes the surface scale of the steel coil test piece for the detection and analysis of subsequent defects. The method of removing the surface scale of the steel coil test piece is more accurate and less destructive to the test piece than the conventional method of removing the scale by mechanical grinding; compared with the conventional method of removing the scale by ion beam etching. , it is more economical and can prepare large-sized test pieces, which is more conducive to the detection and analysis of subsequent defects.

100‧‧‧ method

102‧‧‧Steps

104‧‧‧Steps

106‧‧‧Steps

108‧‧‧Steps

110‧‧‧Steps

112‧‧‧Steps

200‧‧‧ leveling test piece

200'‧‧‧ flat test piece

202‧‧‧Substrate

204‧‧‧rust skin

206‧‧‧rust skin

208‧‧‧rust skin

210‧‧‧ argon ion current

212‧‧‧Area

A better understanding of the aspects of the invention can be obtained from the following detailed description taken in conjunction with the drawings. It should be noted that, according to industry standard practices, the features are not drawn to scale. In fact, in order to make the discussion clearer, the dimensions of each feature can be arbitrarily increased or decreased.

1 is a view showing the steps of a method for detecting a rolling coil defect in accordance with an embodiment of the present invention.

2 and 3 are schematic cross-sectional views showing the steel coil test piece according to an embodiment of the present invention before and after sputtering.

The invention of the present invention combines a technique for generating a glow discharge device to remove the surface scale of the steel coil test piece to prepare a flat surface for the detection and analysis of subsequent defects. The new method established by the invention consists in using a suitable sputtering scale parameter condition to etch the scale layer layer by layer to present the surface between the scale and the substrate interface, so as to facilitate the detection of defects and further Observe and analyze and adjust the parameters of the subsequent pickling process.

Please refer to [Fig. 1, 2, 3] at the same time, [Fig. 1] illustrates the steps of the method for detecting the rolling coil defect in accordance with an embodiment of the present invention, [Fig. 2, 3] A schematic cross-sectional view of a steel coil test piece according to an embodiment of the invention before and after sputtering. Method 100 Series Steel Roll Rolling Defect Detection Method, comprising steps 102-112.

In step 102, a flat test piece is cut from a steel coil, and the length and width are each 4 to 7 cm. The preferred flat test piece has a length and a width of about 4 cm each (ie, 4 cm X 4 cm). The size of the flat test piece is matched with the preferred size of the glow discharge device, and is also suitable for the size of the naked eye or image recognition detection.

In step 104, the flat test piece is placed in a glow discharge device, a voltage is applied to generate glow, and the flat test piece is connected to the negative electrode, and argon gas is introduced to cause the dissociated argon ion (positively charged) to hit the flat test. The surface of the sheet (attached to the negative electrode, so negatively charged) the surface of the scale. The parameter conditions of the glow discharge device are adjusted to a pressure of 600 to 800 Pa and a power of 20 to 40 W, and the surface scale of various steel coils can be removed. In a preferred embodiment, the glow discharge device has a pressure of 650 Pa and a power of 30 W to treat the flat test piece having a length and a width of 4 cm each. The purpose of the parameter adjustment is to control a condition suitable for the argon ion sputtering test piece to obtain a uniform flat surface for subsequent detection of defects.

The glow discharge apparatus used in the present invention is a commercially available glow discharge device, and the above parameters are employed in a glow discharge device manufactured by Horiba Jobin Yvon.

The argon ion impact time from step 106 to step 108 is about 30 to 300 seconds. In a preferred embodiment, the argon ion impact time takes about 150 seconds to effectively remove the scale on the surface of the flat test strip 200.

Referring to [Figs. 2 and 3], the cross section of the flat test piece 200 includes the substrate 202 and the scale layers 204, 206, and 208 having different degrees of oxidation. The scale layer 204 may be, for example, FeO, the scale layer 206 may be, for example, Fe ₃ O ₄ , and the scale layer 208 may be, for example, Fe ₂ O ₃ . The upper and lower order of the above-mentioned scale layer can also be interchanged, and the scale layer with different degrees of oxidation also has different appearances and physical properties. Therefore, the types of defects on the surface of the coil may also contain many different types, which need to be detected and analyzed.

In step 106, the argon ion stream 210 begins to strike (or sputter) the surface of the test piece, and the scale layer of the flat test piece 200 is removed layer by layer.

In step 108, when the argon ion stream 210 is sputtered to the end of the test piece, the scale layer of the region 212 of the flattened test piece 200' has been completely removed, and the surface of the substrate 202 is exposed.

In steps 110 and 112, surface defect detection and physical property analysis of the bare area 212 of the test piece 200' can be performed by naked eye, image recognition or optical or electron microscopy, and appropriate parameter adjustments can be made in the subsequent pickling process, for example, Increasing pickling time, pickling concentration, pickling temperature, pickling tank matching, etc., to solve the related defects of steel coil rolling, so that the final product after rolling can meet the quality requirements.

Applying the method for detecting the rolling defect of the steel coil of the present invention, using the technology of the glow discharge device to remove the surface scale of the steel coil test piece for subsequent defects Detection and analysis. The method of removing the surface scale of the steel coil test piece is more accurate and less destructive to the test piece than the conventional method of removing the scale by mechanical grinding; compared with the conventional method of removing the scale by ion beam etching. , it is more economical and can prepare large-sized test pieces, which is more conducive to the detection and analysis of subsequent defects.

While the invention has been described above in terms of several embodiments, it is not intended to limit the scope of the invention, and the invention may be practiced in various embodiments without departing from the spirit and scope of the invention. The scope of protection of the present invention is defined by the scope of the appended claims.

100‧‧‧ method

102‧‧‧Steps

104‧‧‧Steps

106‧‧‧Steps

108‧‧‧Steps

110‧‧‧Steps

112‧‧‧Steps

Claims (2)

A method for testing a rolling coil rolling defect comprises: cutting a flat test piece on a steel coil, each having a length and a width of 4 to 7 cm, wherein the flat test piece comprises: a substrate; an iron oxide layer Provided on the substrate; a ferroferric oxide layer disposed on the iron oxide layer; and a ferric oxide layer disposed on the ferroferric oxide layer; the flattening test piece is placed in a glow discharge a device, and the flat test piece is connected to the negative electrode, and argon gas is introduced to cause the dissociated argon ion to strike the surface of the flat test piece; the parameter condition of the glow discharge device is adjusted to a pressure of 650 Pa, a power of 30 W, and an argon ion impact. The time is 150 seconds to remove the scale of the flat test piece; and the flat test piece is taken out for detection analysis, wherein the flat test piece impacted by the dissociated argon ion has a uniform flat surface. The method for detecting a rolling defect of a steel coil according to the first aspect of the patent application, wherein the flat test piece has a length and a width of 4 cm each.