In a sense, straight seam steel pipe is a welding process of steel pipe opposite to spiral steel pipe. The welding of straight seam steel pipes is relatively common in the market due to the relatively simple process and low welding cost, which can achieve high efficiency during production. And straight seam steel pipe is a widely used product, so what are the practical advantages of straight seam steel pipe? The straight seam steel pipe is welded by a welding method parallel to the longitudinal direction of the steel pipe, and it is also widely used. For the same diameter and length, the welding length of straight seam steel pipe is much less, while the welding length of spiral steel pipe may increase by more than 30%. During welding, due to process reasons, the efficiency is relatively low, and the output is also quite low. But the same blank, generally spiral welded pipe can obtain products of various diameters. In contrast, straight seam steel pipes cannot achieve this welding effect.
The reason why straight seam steel pipe is widely used in the market is because of its characteristics. Because the process cost used in welding is relatively low, and the production processes of forged steel, extrusion, rolling, and drawn steel can all be manufactured, and the specifications are also determined, it provides a wide range of applications. possibility. To resolutely implement the tough battle of air pollution control, major steel producers have encountered environmental protection storms one after another. In this regard, some analysts believe that the environmental protection governance of the steel industry has entered the implementation stage. In the long run, with the continuous advancement of environmental governance measures, the straight seam steel pipe industry will be labeled as green and environmentally friendly in the future.
In the process of steel pipe production, there are some technical problems with the core pumping machine. How to improve the steel pipe and speed up the production rate is an important issue in front of us. Laboratory experiments cannot solve production problems, and on-site experiments in the workshop are too expensive and cannot be durable. The conclusion that experiments are conducted just once or twice is unreliable. Therefore, it is very important to use the numerical simulation method to study the rolling process of the straight seam steel pipe. At present, in our industry, the rolling speed and the key factor affecting the 5-stand MPM continuous rolling product – the roll gap value is the research objectives, and the relative load description method is used to establish a numerical simulation plan, and the key adjustable parameters (roll gap value) are studied. Through the MARC channel, a finite element model of the rolling process of the straight seam steel pipe was established, and its influence on the rolling force and wall thickness during the rolling process was studied.
In my country, the petrochemical industry, water engineering industry, urban construction, electric power engineering, etc. all have demand for straight seam steel pipes. The diameter expansion of the straight seam welded pipe is a pressure processing process that uses hydraulic or mechanical means to apply force from the inner wall of the steel pipe to expand the steel pipe radially outward. The mechanical method is simpler than the hydraulic method, and the equipment is simple and efficient. Several large-diameter straight seams welded pipe expansion processes in the world are used. The specific introduction of the process is described below.
The mechanical expansion of the straight seam steel pipe utilizes the split sector block at the end of the expansion machine to expand in the radial direction so that the tube blank can be step-by-step along the length direction to realize the process of plastic deformation of the whole tube length. Divided into 5 stages:
1. Preliminary rounding stage. The fan-shaped blocks are opened until all fan-shaped blocks are in contact with the inner wall of the steel pipe. At this time, the radius of each point in the inner circular pipe of the steel pipe within the range of the step size is almost the same, and the steel pipe is initially rounded.
2. Nominal inner diameter stage. The fan-shaped block starts to reduce the movement speed from the front position until it reaches the required position, which is the required inner circumference position of the finished pipe.
3. Repetition compensation stage. The fan-shaped block starts to further reduce the speed at the position of stage 2 until it reaches the required position, which is the inner circumference position of the steel pipe before the rebound required by the process design.
4. Stable pressure holding stage. The inner circumference of the steel pipe remains stationary for some time before the sector block is bounced back, which is the pressure-holding and stable stage required by the equipment and the expansion process.
5. Unloading return stage. The fan-shaped block quickly retracts from the inner circumference of the steel pipe before the rebound until it reaches the initial diameter expansion position, which is the smaller shrinkage diameter of the fan-shaped block required by the expansion process.
Post time: Oct-31-2022