1, cold correction: this is a correction method at room temperature, including mechanical correction and manual correction. Mechanical correction usually uses special pressure machines to correct I-beams. Manual correction depends on the operator's experience and technology, and adjusts the shape of steel by applying force.

2. Heating correction: This method is to correct the steel after heating to a certain temperature. According to the heating conditions, heating correction can be divided into complete heating correction and local heating correction. Total heating correction is to heat the whole steel to a high temperature, while local heating correction is to heat only the parts that need to be corrected.