When we manufacture Q345B square steel pipes, we should pay attention to the following nine issues:
(1) Processing technology manipulation
Manipulation of processing technology should prevent the management center from attenuating and increasing the wall thickness beyond the control limitations. Q345B square pipe welding spatters knowledge of preventive measures and further controls the precision of Q345B square steel pipe wall thickness;
(2) Heating of pipe material
The heating needs to be averaged, and the Q345B square steel pipe discourages the rapid take-off and cooling of the temperature. Every time you take off and cool down, you must persevere and be steady and slow, and the larger take off and drop temperature does not exceed 30 ℃;
(三)Precision of mandrel
The length and slenderness of Q345B square steel tube mandrel is relatively large, Q345B square tube-Q345B seamless square tube-Q345B square steel tube-Q345B cold drawn square tube-Shandong Dingyu Metal Material Co., Ltd. generally chooses the diameter of the first car and then gets rid of the mouth welding, or chooses Long materials are immediately milled to shape. The outer machining accuracy of the mandrel is controlled within ±0 mm, and the straightness of the mandrel is not more than 5 mm. When welding, Q345B square tube welding spatters preventive measures Knowledge Two-segment mandrel pierces a deep-processed pin to carry out precise positioning, Q345B square steel tube avoids "upper cold rolling" or "lower cold rolling", Q345B square tube related specifications and models Smaller mandrels can be replaced by solid core blanks. Thick-walled tubes and solid core blanks with average wall thickness can greatly reduce the probability of bending deformation of the mandrel, and can further improve the thickness precision of the Q345B square steel tube;
(five) relief roll
It is clear whether the reassurance roll equipment can be timely, adjust the center of the core-holding roller, open the angle of view and the size of the teeth of each measure is the same, and the center of the core-holding roller should be on the cold rolling net;
(six) small chain with broken holes
The small chain with broken holes generally selects the thick-walled pipe Q345B square steel pipe with a diameter of Φ108mm-Φ114mm, a wall thickness of ≥25mm and an average wall thickness;
(七)cold-rolled dividing line
Ensure that the cold-rolled separation line of the piercing machine is consistent with the separation line of the broken hole car, avoiding "upper cold rolling" or "lower cold rolling", so that the pipe material can persevere in the hole when the hole is broken;
(八) Cold rolled product equipment
The roll pitch and the middle of the guide pitch must be on the cold rolled wire. The separation line between the inspection opening guide and the roll distance is on the broken hole cold rolling separation line, that is, the left and right roll distances are the same, and the upper and lower guide distances are the same;
(9) Special tools for cold rolling
The special tools for cold rolling of Q345B square steel tubes, such as damaged top edges, reamers, and hot-rolled steel strips, should be replaced immediately.
