Wuxi stainless steel pipe Hot rolling mill Stainless steel seamless pipe Production process
Wuxi stainless steel Pipe mill hot rolling Seamless pipe It can be divided into general steel pipe, low and medium pressure boiler protection steel pipe, high pressure boiler protection steel pipe, alloy steel pipe Stainless steel pipe Oil cracking pipe, etc. Hot rolled seamless steel pipe The main production process is: preparation and inspection of tube blank ¡ú heating of tube blank ¡ú piercing ¡ú pipe rolling ¡ú reheating of raw pipe ¡ú sizing (reducing) of diameter ¡ú heat treatment ¡ú straightening of finished pipe ¡ú finishing ¡ú inspection (nondestructive, physical and chemical, bench inspection) ¡ú warehousing. Round tube blank is rolled seamless steel tube Raw materials. The round tube blank is cut by cutting machine and processed into a bad material with a length of about 1 m, and then it is transported to the melting protection by conveyor belt for heating. The tube blank is sent into the melting protection and heated to about 1200 ¡æ. The temperature control in the furnace is the key. After the tube is discharged from the furnace, it needs to pass through the piercing machine for piercing. Among them, the widely used piercer is the cone-shaped roller piercing steel pipe empty machine, which has high-efficiency production and good product quality. It can be used for piercing of various steel grades. After piercing, the tube blank is successively rolled by three rollers. After extrusion, the tube should be removed for sizing. The sizing machine rotates the conical drill bit into the billet to drill holes at high speed to form a steel pipe (the inner diameter of the steel pipe is determined by the outer diameter length of the drill bit of the sizing machine). After sizing, the steel pipe enters the cooling tower for spray cooling, and then straightens after cooling. Then it is sent to the metal flaw detector through the conveyor belt for internal flaw detection. If there are cracks and bubbles inside the steel pipe, they will be detected immediately. Quality inspection also needs to select the process by hand, after passing the paint spray brush number and specification, etc., and then put into storage.
2.2 problem analysis of stainless steel pouring
? ? A small amount of elements in the stainless steel of Wuxi stainless steel pipe plant are easily oxidized and lead to oxide doping. Because of the high viscosity of molten steel, the nozzle is easily blocked. Due to the poor thermal conductivity of molten steel and the complex solidification morphology of stainless steel, the continuous casting slab is easy to crack. Therefore, the cooling and drawing speed of continuous casting billet are required to ensure the accuracy of operation. In addition, a series of new technologies, such as pouring without oxidation protection, automatic control of liquid level and electromagnetic stirring, have greatly improved the quality of continuous casting billets.
Quality control of stainless steel pipe
? ? Size and position detection technology and automatic control technology. The finishing process and its equipment setting is an important link in the quality control of stainless steel pipe, in which non-destructive testing is the most important means of quality inspection. With the development of technology, more and more manufacturers adopt eddy current and ultrasonic combined flaw detection units, and ultrasonic thickness measuring and laser diameter measuring devices are equipped in the flaw detection units. Before the steel pipe leaves the factory, the steel pipe factory should control the product quality from several links. This kind of combined flaw detection unit has advanced and superb processing system. All the measured signals are processed and stored by computer after being digitized. The degree of automation and production efficiency are quite high.
? ? The weakest link in China's machinery industry is detection and technology control, which greatly hindered the improvement of China's industrial level. Domestic and foreign seamless steel pipe production, has gradually from the pursuit of production in the early stage to improve product quality, reduce production costs. And then there are new equipment and common process. This requires that our steel pipe plants in the premise of updating equipment, dare to improve the implementation of new technology and technology, better improve the quality and level of stainless steel pipe.