The seamless pipe (cs smls pipe) passes through the billet saw section of the steel mill, and then is heated in the ring furnace - perforated - sized - straightened - cooled - saw head - packaged into a qualified finished product. Generally, it cannot be placed in the production workshop when it is delivered to the user. With so much inventory, dealers need to place some inventory, but dealers generally do not have large indoor warehouses, and even if they do, the cost is too high and uneconomical. Most of them are outdoor warehouses. If the seamless steel pipes are placed outdoors, it will inevitably cause wind and sun.
Secondly, seamless steel pipes are generally used in construction and construction. For seamless steel pipes, since seamless steel pipes are also exposed to wind and sun in construction and decoration, this will also lead to rust stains on seamless steel pipes. , Many seamless steel pipes have had a lot of rust stains, which can be divided into rust and floating rust according to the rust stains. So how to distinguish between the two? Next, let's distinguish the relationship between the two:
Floating rust refers to a layer of rust floating on the seamless steel pipe, which can be removed with a towel or other things. Simply put, floating rust is considered to be no rust, which is a normal state. The rust of seamless steel pipes is a long time. At least one year of seamless steel pipes that have been exposed to wind and sun outdoors. There are large and small hemp pits on the rusty seamless steel pipes. The biggest difference in rust.
When there are rust stains on the seamless steel pipe, it is necessary to make a correct judgment first, and then deal with the rust stains. It is necessary to choose a suitable method of rust removal to save the cost for the enterprise as much as possible. Seamless steel pipe is very useful in production and life, and it is used all the time. Seamless steel pipe is a type of steel with relatively good performance.
Go here to learn more about " Commonly Used Rust Removal Methods for Seamless Steel Pipe s "
According to different conditions, the metal material is heated to a suitable temperature and kept warm, and then cooled in different ways to change the metallographic structure of the metal material and obtain the required structural properties. This process is often referred to as heat treatment of metallic materials. What three processes are included in the heat treatment of carbon steel seamless pipes ?
The heat treatment of metal materials is divided into overall heat treatment, surface heat treatment and chemical heat treatment. The heat treatment of seamless steel pipes generally adopts overall heat treatment.
Carbon steel seamless pipes need to go through basic processes such as heating, heat preservation, and cooling during heat treatment. During these processes, defects may appear in the steel pipe. The heat treatment defects of seamless steel pipes mainly include unqualified steel pipe structural performance, unqualified size, surface cracks, scratches, severe oxidation, decarburization, overheating or overburning, etc.
There are three main processes for heat treatment of seamless steel pipes:
The first process of heat treatment of carbon steel seamless pipe is heating.
There are two different heating temperatures: one is heating below the critical point Ac1 or Ac3; the other is heating above the critical point Ac1 or Ac3. Under these two heating temperatures, the structural transformation of the steel pipe is completely different. Heating below the critical point Ac1 or AC3 is mainly to stabilize the structure of the steel and eliminate the internal stress of the steel pipe; heating above Ac1 or Ac3 is to austenitize the steel.
The second process of heat treatment of carbon steel seamless pipe is heat preservation.
Its purpose is to make the heating temperature of the steel pipe uniform to obtain a reasonable heating structure.
The third process of heat treatment of carbon steel seamless pipe is cooling.
The cooling process is the key process of steel pipe heat treatment, which determines the metallographic structure and mechanical properties of the steel pipe after cooling. In actual production, there are various cooling methods for steel pipes. Commonly used cooling methods include furnace cooling, air cooling, oil cooling, polymer cooling, water cooling, etc.
Go here to learn more about " Heat Treatment Process of Thick Wall Seamless Steel Tube "
There are many things that should be paid attention to in the whole heat treatment process of thick-walled seamless steel tube s. For example, the correct setting of the furnace is very important, so as to ensure a smooth cyclone in the furnace, and also make the thick-walled steel tube s receive uniform heat. After that, it can bring very good characteristics. In general, there is no restriction on the ambient temperature during the furnace installation process. In simple terms, it can be a cold furnace or an electric furnace. There are not many limitations in these aspects.
The adoption of the heat treatment process of thick-walled seamless steel tube improves its quality and overcomes the environmental pollution caused by pickling. Let me share with you what is the heat treatment process of thick-walled seamless steel tube ?
(1) Roller hearth bright heat treatment furnace
This type of furnace is suitable for heat treatment of large-scale and large-volume thick-walled seamless steel pipes, and the hourly output is above 1.0t. The protective gas that can be used is high-purity hydrogen, decomposed ammonia and other protective gases. It can be equipped with a convection cooling system for faster cooling of thick-walled seamless steel tube s.
(2) Mesh belt type bright heat treatment furnace
This type of furnace is suitable for small-diameter thin-walled precision thick-walled seamless steel tube s. The hourly output is about 0.3-1.0t, and the length of processed steel tube s can reach 40m. It can also process capillary tubes in coils. Equipped with convection cooling system for rapid cooling. Using gaseous fuel or electric heating, various shielding gases can be used. After this type of furnace heat treatment, the thick-walled seamless steel tube has no scratches and good brightness.
(3) Muffle tube bright heat treatment furnace
The thick-walled seamless steel tube is mounted on a continuous bracket and heated in the muffle tube, which can process high-quality small-diameter thin-walled steel tube at a lower cost, and the hourly output is above 0.3t. Protective gas can be used economically, and the heating source can be gas, oil or electricity.
Most industries have relatively high requirements for seamless steel pipes , and steel pipes need to be purchased in batches during construction. Naturally, it is still necessary to measure the price and pay attention to the choice of manufacturers. So how to choose a reliable seamless pipe manufacturer?
1. Ensure quality
There are too many seamless steel pipe manufacturers on the market at present, so everyone should check its reputation first. Which one is more famous or has better user reviews, then this one is worth choosing. The steel pipes produced by the manufacturers must pass various inspections, and the quality must meet the national standards, so that the later use of steel pipes is guaranteed. Therefore, it is recommended to cooperate with regular manufacturers, so that the other party can provide high-quality seamless steel pipes, and have passed various tests, and the later application will not be affected.
2. Determine the price
The daily price of seamless pipes is characterized by changes. Therefore, when some customers purchase in large quantities, they should immediately pay attention to the market trend in order to find a more cost-effective stage to purchase. Generally speaking, seamless steel pipe manufacturers pay attention to some websites every day, and conduct relevant analysis on the quotations of steel pipes on the websites. Ability to perform relative predictive analysis of market prices for the next week. At this time, when buying, you don't have to follow the trend blindly. You should communicate with the manufacturer about the order information, and learn about the future price trend from the price they predict and analyze. If you are not in a hurry to purchase, you can wait for the low price to submit the order again. For customers who know the price of seamless steel pipes in the market, they can choose the right time to purchase pipes at a low price, which can indeed save a lot of cost in new projects. You can also compare the basic quotations of various manufacturers and choose cost-effective manufacturers for cooperation.
3. Determine the service
The service items that each manufacturer can provide are different. If you cooperate with a local manufacturer, you can generally purchase carbon steel pipes in large quantities and deliver them to your door. After confirming our designated time, the other party will deliver them to your door. If it is long-distance transportation, then it is necessary to determine the arrival time and transportation costs, so as to avoid disputes on costs later. If a seamless steel pipe manufacturer does not even have service items, no matter how good the quality of its products is, various problems may occur in the middle and late stages.
The use of seamless tubes is relatively extensive, and the effect is relatively good. What should be paid attention to in the construction of seamless steel tubes?
1) What kinds of seamless steel pipe materials are there?
There are many kinds, the common ones are the following five: 1. Ordinary carbon structure. 2. High-quality carbon structure. 3. Alloy steel . 4. Stainless acid-resistant steel. 5. Low alloy steel.
Seamless steel tubes are divided into general purpose (for water, gas pipelines and structural parts, mechanical parts) and special purpose (for boilers, geological exploration, bearings, acid resistance, etc.) according to their uses.
2) What should be paid attention to in the construction of seamless steel tubes?
1. In the process of welding seamless steel tube, it is not necessary to use welding branch pipes, and there should be no welds in the bent position, which not only affects the aesthetic effect, but also is not conducive to long-term use, and it is very easy to cause leakage.
2. Special attention should also be paid to the welding joint of seamless steel pipe. It must be straight and full, and the surface of the welding joint must not have defects such as burn-through, cracking, nodules, and pores, otherwise it will affect Later use will bring unnecessary trouble.
3. The welding wave of the seamless steel tube must be consistent, and the error caused by the misalignment of the pipe must be controlled at about 20% of the wall thickness and within the range of 2mm. If it exceeds this value, it will affect the later use.
4. During the welding process, it is necessary to ensure that there will be no bending at the position of the welding joint, and no wrong joints will occur. Then there is the positioning of electric welding, which is to carry out spot welding at four points, and after straightening, it is necessary to use the form of free conversion to carry out welding work.