At present, the flatness of 304 stainless steel plate really needs to be improved, which depends on the flattening machine. If it is imported, the tablet of tens of millions of tablet machines is very flat, especially the 3mm tablet is as straight as a mirror. But if it were millions of ordinary people, it might not be so straight. For demanding stainless steel applications, flat panel manufacturers place great importance on flatness.
The flatness error of 304 stainless steel plate refers to the change of the measured actual steel plate surface relative to its ideal plane. The location of the ideal plane should satisfy the minimum conditions. The flatness error belongs to the shape error in the shape and position error. There are five common methods for measuring the flatness error of 304 stainless steel plate:
1. Flat crystal interferometric measurement: The working surface of the optical flat crystal is used to reflect the ideal plane, and the flatness error value of the surface of the tested steel plate is directly determined according to the bending degree of the interference fringes. It is mainly used to measure the flatness error of small planes, such as the surface of 304 stainless steel plate and the measurement surface of micrometer needle.
2. Scribing measurement method: The scribing measurement method is to place the tested 304 stainless steel plate and a micrometer on a standard steel plate, take the standard steel plate as the measurement reference plane, and use a micrometer to measure along the actual surface point by point or along several straight lines. The tabulation measurement method is divided into the three-point method and the diagonal method according to the evaluation datum: the three-point method takes the ideal plane determined by the three farthest points on the actual surface to be measured as the evaluation datum. During actual measurement, the three farthest points on the actual surface to be measured should be adjusted to the same height as the standard steel plate; when using the diagonal method, firstly adjust the four corners on the actual surface to two points according to the diagonal. an equal height. Then measure with a micrometer. The largest variation measured by the micrometer across the actual surface is the flatness error of the actual surface of the steel plate.
3. Liquid level method: The liquid level method takes the liquid level as the measurement datum, which consists of the liquid level in the connection tank and is measured with a sensor. This method is mainly used to measure the flatness error of large flat steel plates.
4. Beam surface method: The beam surface method is to use the quasi-value telescope and sight to measure, and select the beam surface formed by the three farthest points on the actual surface as the measurement reference surface of the flatness error.
5. Laser flatness measuring instrument: The laser flatness measuring instrument is used to measure the flatness error of 304 stainless steel slabs.