What is the difference between hot straightening and cold straightening of H-beam in H-beam fabrication?

In the production process of H-beam,due to the welding process,the workpiece will be heated and deformed.In order not to affect the normal use of the workpiece,after welding must be corrected.Before the traditional process is to weld after the completion of the straightening machine,at this time the workpiece has returned to normal temperature,the mechanical straightening roller for extrusion correction,is cold straightening.When the workpiece is corrected at high temperature,it is called hot straightening.            

When the contact surface between the flange and the web is heated,the heat on one side and natural cooling on the other side will lead to the ship shape deformation,and the two edges of the flange plate will bend towards the web.Heating on one side of the bottom plate causes angular deformation of the bottom plate due to uneven heating in the thickness direction,which also exceeds the process requirements.Enter the H-beam straightening machine, and then pull it back to the normal straight state to meet the process requirements.

Cold straightening requires independent equipment and independent operation procedures,which increases the production cost and labor cost,not only reduces the work efficiency, but also increases the hoisting risk during operation. Moreover,the secondary failure of the steel structure of the workpiece increases the fatigue damage times of the steel.

H-beam welding and straightening machine can be used for thermal correction of workpiece.Thermal correction refers to that the workpiece enters the correction process within two or three seconds after welding.The correction system is more through the operation of the upper and lower rollers to limit the flange plate,to prevent its deformation,not to give the wing plate deformation opportunity.After coming out of the correction system,it has been working at room temperature, and there is no possibility of deformation.

Compared with the cold straightening,the hot straightening is completed by the H-beam welding and straightening machine with one equipment simultaneously.It improves the output,improves the work efficiency,saves the labor cost,reduces the operation risk,and ensures the steel quality of the workpiece material better.