What is weathering steel?Weathering steel is a low-alloy high-strength steel that has a small amount of alloying elements to make it have good corrosion resistance in the atmosphere. The weathering resistance of weathering steel is 2 to 8 times that of ordinary carbon steel, and the longer it is used, the more prominent the corrosion resistance. In addition to good weather resistance, weathering s...

Technological approaches to improve the plasticity of forgings and reduce the resistance to deformation To facilitate the flow of metal billets during forging, and to take reasonable measures to reduce deformation resistance and save equipment energy, the following methods are generally used to achieve:1) Grasp the material characteristics of forgings, and choose a reasonable deformation temperatu...

1) In the code area of the austenite isothermal transformation diagram, that is, about 500-600 ℃, the water is in the vapor film stage, and the cooling rate is not fast enough, which often results in "soft spots" formed by uneven cooling of the forgings and insufficient cooling rate. . In the martensite transformation system, that is, about 300-100 ° C, the water is in the boiling stage, the cooli...

In the heat treatment of forgings, due to the high power of the electric furnace and the long holding time, the energy consumption is huge throughout the process. For a long period of time, how to save energy during heat treatment of forgings has always been a problem.The so-called "zero heat preservation" quenching refers to the heat treatment process in which the surface and core of the forging ...

The ultra-low carbon Ni-Cr-Mo system with Cr and Mo as main alloying elements is also called Hastelloy system. Hastelloy is a trademark of Haynes International, Inc., consisting of HA in HAYNES, STELL in STEI.LITE and OY in ALLOYS. Hastelloy, as an advanced nickel-based alloy, has excellent corrosion resistance to a variety of harsh corrosive environments, such as wet oxygen, sulfurous acid, and s...

The Ni-Cr-Fe system has a lower Fe content as an Inconel alloy, and a higher Fe content has an Incoloy alloy. Incoloy alloys are actually Fe-Ni-Cr alloys in nickel-based alloys because of their Fe content up to 45%. The casting alloy of Inconel alloy is CY240, and the grade of rolled material is Ineonel 600. Ineoloy alloy rolled grade is Incoloy 800 alloy. In the current corrosion-resistant nickel...

Ni and Cu can be mixed in any ratio to form a solid solution alloy, which is called Monel alloy. Ni-Cu has good resistance to HF, seawater brine and crevice corrosion. Monel alloy Ni70Cu30 is the earliest nickel-based corrosion resistant alloy. It has both high strength and toughness, and excellent resistance to corrosion by reducing acids and strong alkaline media and seawater.It is usually used ...

First, the principle of pickling passivationThe corrosion resistance of stainless steel is mainly due to the higher content of Cr added to the steel (such as 316L W (Cr) = 16.00 ～ 18.00). Cr is easily oxidized and can form a dense Cr2O3 oxide film on the surface of the steel. The electrode potential of the steel and the corrosion resistance in the oxidizing medium are suddenly improved. The corros...

1. Improve or eliminate various structural defects and residual stress caused by steel during casting, forging, rolling and welding, and prevent deformation and cracking of the workpiece.2. Soften the workpiece for cutting.3. Refine the grains and improve the structure to improve the mechanical properties of the workpiece.4. Prepare the structure for final heat treatment (quenching, tempering).

1. Improve the stability of the organization, so that the workpiece no longer undergoes structural transformation during use, so that the geometry and performance of the workpiece remain stable.2. Eliminate internal stress in order to improve the performance of the workpiece and stabilize the workpiece geometry.3. Adjust the mechanical properties of steel to meet the requirements of use.

1) Improve the mechanical properties of metal products or parts. For example: improve the hardness and wear resistance of tools, bearings, etc., increase the elastic limit of springs, and improve the comprehensive mechanical properties of shaft parts.2) Improve the material properties or chemical properties of some special steels. Such as improving the corrosion resistance of stainless steel and i...

This type of steel was developed in the late 1980s. The grades are mainly SAF2507, UR52N, Zeron100, etc. It is characterized by low C content, high Mo and high N, and ferrite phase content in steel accounts for 40% to 45%. , has excellent corrosion resistance.

It inherits the characteristics of high strength, good oxidation resistance and excellent stress corrosion resistance of ordinary ferritic stainless steel, and improves the ductility of brittle-brittle transition, sensitivity to intergranular corrosion and low toughness of welded state. Refining technology, reducing C and N content, adding stabilizing and weld metal toughening elements, can obtain...

It is a hardenable stainless steel with high hardness, strength and wear resistance, but has poor toughness and weldability. Ordinary martensitic stainless steel lacks sufficient ductility and is very sensitive to stress during deformation, and cold forming is difficult. Super martensitic stainless steel can be obtained by reducing the carbon content and increasing the nickel content. In recent ye...

In addition to excellent corrosion resistance, 316 stainless steel forgings also have high strength, high hardness, high wear resistance, wide operating temperature range (up to 500~550 °C, as low as -253 °C) and good process plasticity. Etc. 316 stainless steel forgings contain a large amount of alloying elements such as nickel and chrome. The processing in the forging factory can significantly c...

Near-isothermal forging technology is an advanced forging technique that solves the problem of forming some low-plasticity and difficult-to-deform materials. This technology is developed on the basis of the idea of isothermal forging technology. The biggest difference from isothermal forging is that the mold is heated to a temperature lower than the workpiece temperature of about 30-80 ° C and for...

Roll forging is a plastic forming process in which a material is plastically deformed by a pair of rotating molds in the opposite direction to obtain a desired forging or forging blank. As an advanced plastic forming process, roll forging has a series of advantages such as high material utilization rate, excellent product quality, good working conditions, easy realization of mechanical automation,...

A multi-forging die forging method has certain constraints (or unsuitable conditions), as long as one of the following contents is not suitable for one-time multi-forging (especially unsuitable for one-die multi-forging, continuous multi-forging, turning forging and forging) Forming die forging and other forming methods): If the weight of the forging is large, the horizontal projection area of the...

Precision forging refers to the forming technology that meets the dimensional accuracy requirements of parts without a small amount of machining or machining. There are two main ways to achieve precision forging: refined blanks, that is, directly forged blanks that meet the requirements of precision machining. Precision forgings, all or parts of the parts are directly processed by precision forgin...

The main role of nickel content in stainless steel is that it changes the crystal structure of the steel. One of the main reasons for the addition of nickel in stainless steel is the formation of austenitic crystal structures, which improve the properties of stainless steels such as plasticity, weldability and toughness, so nickel is called an austenite forming element.The crystal structure of ord...

The precision rolled is also called cold-rolled precision steel pipe, which is a production process of seamless steel pipe.Finished tube features:1. Cold-rolled precision steel pipe has high tolerance and dimensional accuracy, and the product precision is controlled at ±0.05mm.The inner and outer walls have a good finish and no oxide layer on the surface.2. Cold-rolled precision steel pipe has exc...

Cold drawing is to pull out the metal pipe with a cold drawing machine without heating. The advantage is that it does not need to be carried out at high temperature. The disadvantage is that the residual stress is large, and it can not be pulled too long to improve the toughness and tensile strength. Get better mechanical properties.Cold drawn seamless steel pipe process:Round tube blank → heating...

Cause of formationDuring the casting process, the metal strips, blocks, and pieces fall into the ingot mold or the iron alloy added at the end of the smelting is not melted.Macroscopic featuresOn the etched sheet, there are many geometric shapes with sharp edges and distinct colors from the surrounding.

Cause of formationDuring the solidification process, the steel fails to be welded during the hot working process due to the final solidification shrinkage of the low melting point material and the voiding of the evolved gas. According to its distribution, it can be divided into two categories: center and general porosity.Macroscopic featuresOn the lateral hot acid immersion surface, the pores are ...

Cause of formationDuring the casting solidification process, the aggregation of certain elements is caused by the selection of crystallization and diffusion, resulting in uneven chemical composition. According to the different positions of the distribution, it can be divided into ingot type, center and point segregation. Macroscopic featuresOn the acid immersion sample, when the segregation is an ...

What elements will effect heat treatment for forgings?1, size effect:The mechanical properties of forged steel vary with the shape and size. Generally, the larger the size, the shallower the depth of heat treatment in the same cooling medium, and the lower the mechanical properties.2. Mass effect:The quality (weight) of the forgings is different, and the final result of the heat treatment is diffe...

Stainless steel is an iron alloy, which means that iron is combined with other materials to form a new metal. This means that different combinations can have different properties, and be used for different things. Stainless steel can be magnetic in some cases, when these materials are combined in different ways. One of the most common types of stainless steel is called “ferritic” stainless steel,...

Stainless steel (also known as “inox steel”) is used in many modern applications because of its remarkable strength, temperature resistance, and ability to resist corrosion and rust. These qualities make stainless steel ideal for use in a wide variety of products, from kitchen knives to construction materials. The stainless steel industry has grown an average of 5% between 1980 and today, and pro...

The VD refining method is a steel liquid vacuum treatment method in which an initial electric steel of an electric furnace and a converter is placed in a closed tank to evacuate, and a argon is stirred at the bottom of the ladle. In the electric furnace, converter, after melting, preliminary blowing, and then placed in a vacuum tank (vacuum chamber) by bottom argon stirring and vacuum degassing pr...

LF furnace (LADLE FURNACE) is a ladle refining furnace, which is the main refining equipment in steel production. The LF furnace refining mainly relies on the white slag in the barrel, and in a low-oxygen atmosphere (oxygen content is 5%), argon gas is blown into the barrel to be stirred, and the graphite electrode is heated to refine the molten steel passing through the preliminary furnace. Since...

Vacuum induction melting, referred to as VIM, a metallurgical method for generating eddy current heating in a metal conductor by electromagnetic induction under vacuum conditions. The VIM process has a small volume of the melting chamber, a short vacuuming time and a short melting cycle, and is convenient for temperature and pressure control, recyclable volatile elements, and accurate control of a...

The rolled billet must be cut, because: a, should cut off the shrinkage hole part or the head part of the steel ingot; b, cut off the uneven deformation part of the steel ingot tail; c, in order to meet the fixed length of the finished product It is required that the ingot must be cut to a fixed length; d, is also required to be cut due to the limitations of the process and equipment conditions of...

Steel finishing is an indispensable process in the rolling steel production process. The purpose of finishing is to ultimately guarantee product quality. Finishing includes all the operations of rolling steel after cooling (such as slow cooling, etc.), heat treatment, straightening, pickling, cleaning, grading, and packaging until the finished product warehouse. Due to the technical requirements o...

Depending on the chemical composition of the steel, the state of the structure, the size of the product, the possible defects after cooling, and the conditions of the mill output, cooling site and cooling equipment, the hot rolled steel can be cooled to room temperature by different cooling methods.1) Air Cooling This is a method of natural cooling in the air, which is widely used. After cooling i...

O (oxygen)O is a harmful element in steel. It naturally enters the steel during the steelmaking process. Although manganese, silicon, iron and aluminum are added for deoxidation at the end of steelmaking, it is impossible to remove. During the solidification of molten steel, the reaction of oxygen and carbon in the solution generates carbon monoxide, which can cause bubbles. Oxygen is mainly prese...

N (nitrogen)The effect of N on the properties of steel is similar to that of carbon and phosphorus. With the increase of nitrogen content, the strength of steel can be significantly improved, the plasticity, especially the toughness, is also significantly reduced, the weldability is deteriorated, the cold and brittleness is intensified, and the aging tendency is increased. Cold brittleness and hot...

C (Carbon)C is the main element after iron, which directly affects the strength, ductility, toughness and weldability of steel.When the carbon content in the steel is below 0.8%, the strength and hardness of the steel increase with the increase of carbon content, while the plasticity and toughness decrease; but when the carbon content is above 1.0%, with the carbon content When the increase, the s...

B (boron)The main role of B in steel is to increase the hardenability of steel, thereby saving other less expensive metals, and nickel, chromium, molybdenum and the like. For this purpose, the content is generally specified in the range of 0.001% to 0.005%. It can replace 1.6% nickel, 0.3% chromium or 0.2% molybdenum. Boron molybdenum should be noted that molybdenum can prevent or reduce temper br...

H (hydrogen)H is the most harmful element in general steel. Hydrogen dissolved in steel can cause defects such as hydrogen embrittlement and white spots in steel. Like oxygen and nitrogen, hydrogen has very little solubility in solid steel. It dissolves in molten steel at high temperatures. When it cools, it does not reach out and accumulates in the structure to form high-pressure fine pores, whic...

All stainless steel products are 100% recyclable. Many recycling companies will want the various grade types to be kept separate (all 300 series together etc.). The typical re-melt rate for stainless steel is between 60 and 85%.