Excellent properties when properly heat treated. Sharpening blog Stainless steel 40x13

One of the most demanded materials in the field human activity is steel. An alloy of iron and carbon has unique technical characteristics, thanks to which the versatility of this material is ensured. And among the best are specifications steel 40x13, which is why it is used in a fairly large number of production processes.

Steel marking

In order to understand the characteristics inherent in the presented material, it is necessary to understand what its labeling means. There are a large number of steels in the world, all differ in their properties. Moreover, every day a new brand of material can be produced. Therefore, you should understand the abbreviation of the product.

Steel 40x13 is alloyed, that is, in its composition, in addition to carbon and iron, there are other active elements. In this case, chrome is contained: this is indicated by the letter X in the marking. Its percentage is 1.3 percent. But the technical characteristics of 40x13 steel depend mainly on the amount of carbon contained in it. In this case, the material contains 0.40 percent of the element with atomic number 6.

Alloy steel production

Alloy steel production technology includes several stages, which are mainly carried out in electric arc furnaces:

  1. Refining of iron ore.
  2. Smelt steel.
  3. Introduction of additional additives.

First of all, iron ore is purified: they get rid of foreign components, mainly sulfur and phosphorus. This process is carried out in open smelting furnaces using out-of-furnace processing technology. Refining process - removal of arsenic and impurities of non-ferrous metals from the composition. It is carried out by means of vacuum melting.

The next stage in the manufacture of an alloyed steel grade consists directly in the smelting of the steel product. For this, the raw materials are heated in an electric arc furnace to a temperature of 400 to 600 degrees. During melting, iron turns into cast iron, which has an unstable crystal lattice. By stabilizing it, steel is obtained.

To do this, oxygen is supplied to the chamber, which, when burned, emits carbon into the atmosphere of the furnace. It, mixing with iron, converts cast iron into steel. After that, dissimilar additives (in our case, chromium) are added to the raw materials. As a result, the crystal lattice of the metal product becomes even more dense, and an alloyed product is obtained.

Specifications

The smelting of the alloy steel is followed by the process of quenching and tempering the sample. The sample is hardened at a temperature of 1100 degrees. After that, it is important to observe a gradual vacation, otherwise the sample will be covered with cracks. To prevent this from happening, this event is held at a temperature of 600 degrees.

Thanks to this manufacturing process, the final product has the following technical characteristics:

  1. Ultimate tensile strength - 1140 MPa.
  2. The conventional yield point at permanent deformation is 910 MPa.
  3. Elongation - 12.5 percent for five times the length of the sample.
  4. Impact strength - 12 J /.

These characteristics allow the material to be used in various spheres of human activity.

Application

The industry has found widespread use of steel 40x13. It is mainly used in humid environments. The chromium contained in it enhances the anti-corrosion properties obtained from conventional hardening.

The presented brand has good indicators of plasticity: at temperatures over 1000 degrees, it is easy to deform. This material is actively used in the production of cutting and measuring tools, household items.

The characteristics of 40x13 steel made it possible to use it in the production of machine parts, mainly bearings and compressor parts. The main condition for using ready-made elements is that the temperature of the working environment should not exceed 400 degrees. In construction, the material is practically not used, because it is not welded.

Anti-corrosion performance and their effect on the use of steel

Steel 40x13 GOST has distinctive indicators of corrosion resistance. It is achieved by quenching the product from a temperature at which the complete dissolution of carbides is ensured. But, if, after heat treatment, the tempering temperature is increased, there will be a decrease in corrosion resistance due to the volatilization of chromium from the material. A decrease in parameters occurs when the release temperature is above 600 degrees.

As a result, in order to obtain more favorable technical characteristics of 40x13 steel, it must be released at temperatures from 200 to 300 degrees in order to obtain high rates hardness and corrosion resistance, or at a temperature of 600-650 Celsius units - to convert the product into steel for structural purposes.

"Work-hardened, heat-treated grinded rods from high-alloy and corrosion-resistant steel. Specifications.";
GOST 5582-75 "Corrosion-resistant, heat-resistant and heat-resistant rolled products. Technical conditions";
GOST 5632-72 "High-alloy steels and corrosion-resistant, heat-resistant and heat-resistant alloys. Grades";
GOST 5949-75 "Sorted and calibrated corrosion-resistant, heat-resistant and heat-resistant steel. Technical conditions";
TU 14-1-2186-77;
GOST 4405-75
GOST 14955-77 "High quality round steel with a special surface finish. Specifications.";
GOST 2590-2006 "Hot-rolled steel bars. Range of products.";
GOST 2591-2006 "Hot-rolled square bar steel. Product mix.";
GOST 7417-75 "Calibrated round steel. Range.";
GOST 4405-75 "Hot-rolled and forged strips of tool steel. Range.";
GOST 8559-75 "Calibrated square steel. Range.";
GOST 8560-78 "Calibrated hexagonal rolled products. Range.";
GOST 1133-71 "Forged round and square steel. Range.";
GOST 5632-72 "High-alloy steels and corrosion-resistant alloys, heat-resistant and heat-resistant. Grades.";
GOST 103-2006 "Hot-rolled steel bars. Range.";
GOST 5949-75 "Graded and calibrated corrosion-resistant, heat-resistant and heat-resistant steel. Specifications.";
GOST 2879-2006 "Hot-rolled hexagonal steel bars. Range.";
TU 14-11-245-88 "High precision steel shaped profiles. Technical conditions.";
OST 3-1686-90 "Billets from structural steel for mechanical engineering. General specifications.";

Chemical composition of steel 40X13

C Cr Fe Mn P S Si
0,36-0,45 12-14,0 Main≤0,8 ≤0,030 ≤0,025 ≤0,8

Mechanical properties of steel 40X13

Normalized mechanical properties at 20 ° C


GOST

Product type

Heat treatment mode

σ in, N / mm²

δ 5,%

Thin sheet

Grade Ø, ¤ up to 200 mm Calibrated steel

Annealing or vacation

Quenching: from 950-1050 ° C; from 1000-1050 ° C, cooling in oil; tempering at 200-300 ° С, cooling in air or in oil

Tape δ = 0.2-2 mm

Annealing or tempering at 740-800 ° С

δ < 0,2 мм

Mechanical properties at elevated temperatures


t isp, ° С

σ in, N / mm²

σ 0.2, N / mm²

δ 5,%

KCU, J / cm 2

t isp, ° С

σ in, N / mm²

σ 0.2, N / mm²

δ 5,%

KCU, J / cm 2

Steel 30X13 (quenching from 1000 ° C in air, tempering at 650 ° C)

Steel 40X13 (quenching from 1050 ° C in air, tempering at 600 ° C, hardness 311-331 HB)

Steel 40X13 (quenching from 1050 ° C in air, tempering at 650 ° C, hardness 277-286 HB)

Physical properties of steel 40X13

Physical properties

Corrosion resistance of steel 40X13

Steels 30X13 and 40X13 have the best corrosion resistance after quenching from a temperature that ensures complete dissolution of carbides. An increase in the tempering temperature is accompanied by a decrease in their resistance to general corrosion. The reason for the decrease in corrosion resistance is the depletion of the solid solution in chromium due to the precipitation of chromium carbides. At the same time, the corrosion resistance of 40X13 steel is slightly lower than that of 30X13 steel. A decrease in corrosion resistance is observed upon tempering up to 600 ° C, then its slight increase occurs. However, the corrosion resistance does not reach the level that both steels have in the hardened or low-strain state.
Thus, it is advisable to use steels 30X13 and 40X13 either after temperature tempering at 200-400 ° C (in order to obtain high hardness and corrosion resistance), or after high tempering at 600-650 ° C in order to obtain a structural material.

The structure of steel 40X13

In the hardened state, the microstructure consists of martensite and carbides and a small amount of retained austenite. When heated above the temperature A c3, the structure consists of austenite and chromium carbides of the M 23 C 6 type. Starting from a quenching temperature of 1050 ° C and higher, the hardness of steel (30X13) does not increase and even tends to decrease, which indicates an increase in the amount of retained austenite.
Tempering hardened steel of both grades leads to the decomposition of martensite into a ferrite-carbide mixture and to a decrease in hardness. However, in the tempering temperature range of 450-550 ° C, the effect of secondary hardness is observed, associated with the precipitation of dispersed carbides.
Critical points for both steels: A c1 = 820 ° C; A c3 = 860-880 ° C; MH = 270 ° C; MK = 80 ° C.

Technological parameters 40X13

Steels 30X13 and 40X13 are well exposed to hot plastic deformation, which is carried out in the range of 1100-850 ° C. Steels are prone to cracking at rapid heating and cooling rates. In this regard, when heating for hot deformation, slow heating to 830 ° C is used, and after deformation, slow cooling in a stack, sand or in a furnace. Cold plastic deformation of steels is limited, especially steel 40X13. As a softening heat treatment after hot deformation, intermediate annealing at 740-800 ° C or complete annealing at 810880 ° C is used, followed by slow cooling at 25-50 ° C / h to 600 ° C. After cold plastic deformation, annealing at 750 ° C.
The final heat treatment is quenching from 950-1050 ° C with cooling in oil or air and tempering to the specified hardness and corrosion resistance. For steels used for the manufacture of surgical instruments, it is recommended to stepwise hardening from 1020-1040 ° C, followed by cooling in alkali at 350 ° C in order to reduce warpage and increase elastic properties.

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Any steel has certain properties inherent only in a particular brand. And metallurgists are trying to make every effort to obtain the highest and quality characteristics of the material. But, since it is not entirely realistic to obtain an ideal steel structure, it all comes down to the selection of optimal opportunities for certain purposes. After all, everyone knows that a knife made of mild steel is easier to sharpen than one that is made of a harder one. A solid steel on the contrary, it is highly resistant to mechanical stress.

With a complex chemical composition, it also slows down manufacturing process steel making, which is why the cost finished product growing.

The quality of a knife may not always depend on a specific steel grade. Plays an important role here high-quality heat treatment of the product... The most demanded steel for making knives is considered to be 40x13 steel. It has all the necessary properties and characteristics.

What are the characteristics of steel 40x13

Steel grade 40x13 has the following characteristics:

Steel acquires its anti-corrosion properties due to a complex technological process, which provides for a special hardening. As a result of this procedure, complete dissolution of carbide, which provides anti-corrosion protection of the material. One of the reasons for the decrease in corrosion resistance is a low chromium content in carbide or a decrease in the melting temperature of steel to 600 degrees. But, if the technological process is provided correctly, then this should not happen.

Steel is melted in special open-type furnaces. Induction ovens can also be used for this. Process melting of steel is carried out at temperatures from 850 to 1100 degrees, which ensures its complete deformation. To prevent cracks from forming, the technological procedure provides for special heating and cooling modes, which are carried out alternately.

Components after hardening

After the steel has passed the hardening procedure, its components are the following elements:

After reaching the temperature limit of 1050 degrees and above, a decrease in the hardness of the material is observed. This indicates an increase in the amount of austenite in the composition of the steel. With a decrease in melting temperatures to 450-550 degrees secondary hardness of the material is observed, which occurs as a result of the separation of finely dispersed carbide from the steel composition.

Scope of steel 40x13

Steel grade 40x13 is widely used for the manufacture of inexpensive domestic kitchen knives. Products made from this steel are perfect for use in the household, since they do not rust under any circumstances, they are easy to sharpen and are convenient both in use and in maintenance. With a knife with such steel, you can easily cut all types of gastronomic products, meat, fish, vegetables and fruits. Such a blade is not only sharp enough, but also completely safe for use for food purposes.

Moreover, 40x13 steel is used for the production of medical scalpels and other tools. Measuring devices, springs, bearings, compressor elements and other items that are applicable in the household are made from it.

The only drawback of products made of such steel is such a factor as instability to aggressive environments and high temperature conditions. Therefore, this type of steel is prohibited for use in welding.

What reviews do products from steel 40x13 use?

Products made of 40x13 steel are in great demand among a wide range of consumers. Therefore, the production of this steel grade occupies an important place in metallurgy. Many people say that knives made of such material very durable due to their hardness... The blades sharpen well and stay sharp for a long time. In addition, steel does not corrode, which further increases its market demand. Moreover, products made from it have an acceptable cost compared to its other counterparts.

Divers, fishermen, divers and just housewives are especially fond of steel 40x13. After all, knives made from this steel are really practical for use in various industries. Souvenir blades are also successfully produced from it.

It should be noted that products made of steel material do not require any special maintenance at all, except for sharpening. But 40x13 steel requires careful handling as the blades of the knives are very flexible. For example, you cannot use such a knife on hard surfaces.

Particularly popular is a manicure tool made of a material such as 40x13 steel. Due to its hardness, the tweezers work well on the cuticle. However, do not sharpen the tool frequently. And its constant use does not lead to deformation of the product.

They are especially satisfied with the quality of the blades and medical workers in particular surgeons. After all scalpels are made mainly of steel 40x13... It even acquired a new name - medical steel.

When purchasing products made of 40x13 steel, you need to remember that you need to be careful about things. Knife blades do not like storage in damp and very humid conditions. Small spots of rust may appear on them, which, of course, will disappear after sharpening. But, it is better not to allow such oversights.

For several years now I have been using a kitchen knife made of 40x13 steel. And I want to say that a knife made of such material is quite durable and convenient to use. It is good and easy to sharpen. Perfectly cuts even tough meat and fish. Its durability is striking. The blade did not wear off at all with constant use.

Elena Oryol

I have been working as a manicure master for 10 years. In my work, I had to use various cutting tools to give the nails the desired shape and neat appearance... I was especially pleased with the cuticle trimming tweezers made of 40x13 steel. The material is quite durable, remains sharp for a long time, does not deform during sharpening.

Svetlana, Yekaterinburg

The market offered to buy a bearing for a bicycle made of 40x13 steel. I was very pleased. It turned out to be quite durable and high quality. Highly recommend!

Any material, including steel, has certain properties that are unique to it. Specialists in the development of new grades of steel go to great lengths to obtain optimum properties and characteristics. This fully applies to steel 40X13.

Main characteristics

Steel 40X13, sometimes referred to as 4X13, is referred to as corrosion-resistant, heat-resistant grades. The domestic substitute is steel 30X13. V chemical composition This material includes:

  • carbon up to 0.45%;
  • chromium up to 14%;
  • other materials (silicon, manganese, etc.) up to 0.8%.

This composition makes it possible to manufacture the following products from this steel:

  • cutting and measuring tools;
  • medical, including surgical instruments;
  • structural elements operating in weak corrosive environments.
  • springs, fasteners, shafts, bearings capable of operating in aggressive environments, including temperatures up to 450 ºC.

This material is obtained in open ovens. The most commonly used induction furnaces. Steel is melted at temperatures ranging from 850 to 110 degrees Celsius. This mode ensures its complete deformation. To prevent the formation of cracks and other defects, various temperature conditions are used, applied alternately. By the way, for the use of parts from grade 40X13 in aggressive environments, in order to increase its resistance to corrosion, it is recommended to grind their surface.

Steel of this grade is unacceptable to be used to create structures using any type of welding.

Analogs

Among the imported analogues of steel grade 40x13 are the following:

  • USA - 420;
  • Germany - 1.4031;
  • PRC - 4S13.

GOST

The metallurgical industry produces the following assortment - sheet (GOST 5582-75), bar GOST 18907-73, wire (GOST 18143-72).

Heat treatment of steel

The 40X13 brand receives its unique properties, in particular, increased resistance to corrosion, as a result of complex heat treatment.

After hardening, the constituent components of 40X13 steel are:

  • carbides;
  • martensites;
  • remnants of austenites.

It should be noted that at a temperature of about 1050 ºC, steel loses its hardness. This is primarily due to the fact that in this mode the amount of austenite increases. But when the temperature drops to 500 ºC, the hardness returns. This is due to the removal of carbides from the steel structure.

Final heat treatment (hardening) is carried out at a temperature of 950 - 1000 ºC, followed by cooling in oil or air. If all technological modes are observed, steel will obtain the required hardness and corrosion resistance.

Technological properties of steel 40X13

The 40X13 grade has good manufacturability when carrying out plastic deformation in the hot state. It is carried out at temperatures from 850 to 1100 ºC. But we must remember that with a sharp heating, steel can lose a number of its unique properties, for example, hardness. That is why the heating procedure must be carried out at a low speed. Once the temperature reaches 830 ºC, rolling or forging can be done. Cooling of steel must also be carried out slowly.

Steel 40X13 is poorly subjected to cold deformation.

A number of characteristics of corrosion-resistant steel and carbon steel are similar in many ways, in particular in terms of hardness. But they have a different microstructure and this leads to the appearance of certain difficulties in the process of machining.

The main difficulties arising during turning and milling of steel grade 40X13 are:

  • hardening arising during the cutting process;
  • disposal of processing waste;
  • accelerated wear of the cutting tool.

The fact is that when machining 40x13 by cutting, the chips do not break like most carbon steels, but curl in the form of long chips. To solve this problem, special devices are installed on the cutting tool - chip breakers.

Low thermal conductivity is good when using 40X13 in practice, but creates certain difficulties when turning. That is, the temperature rises sharply at the place of processing, as a result of which the formation of work hardening and uneven hardening of the surface occurs. This property of steel leads to a decrease in the resource of the cutting tool and an increase in the processing of the part.

Another property of 40X13 is the presence in its composition of carbide and other compounds that have a microscopic size. Their presence makes steel a kind of abrasive, which puts the cutting tool out of order and this leads to a slowdown in processing.

For effective processing of stainless steel, a cutting tool is used, on the surface of which tungsten carbide and other hardening coatings are applied.

Application of steel 40X13

The unique properties of this steel grade made it possible to use it in aircraft construction. The fact is that the industry is constantly in need of materials that are highly durable when operated at high temperatures, such as an aircraft engine. In addition, in modern aviation technology, parts made of this steel are used in the load-bearing elements of the fuselage structure, etc.

Grade 40X13-X12MF1 is a composite steel, which includes components from the name itself, therefore, when discussing the characteristics of this steel as a material for making knives, you must first describe the properties of each component separately.

Steel grade 40X13 in everyday life is often called "medical" steel, because it is used to make surgical instruments, in particular scalpels. In the industry, cutting tools, springs, bearings, and also measuring tools are made of steel grade 40X13, since this steel holds its shape very well in a significant temperature range.

Heat-resistant, wear-resistant and corrosion-resistant steel 40X13 finds itself in a wider application, from which excellent blades are obtained for household, hunting knives and various categories of edged weapons. The blades of knives made of 40X13 steel are considered relatively "soft", therefore they lend themselves well to sharpening, but they do not hold it too long. With proper hardening, higher hardness marks (~ 58HRC) can be achieved, but the ductility of the steel suffers greatly.

Composition of steel grade 40X13:

The second component of composite steel 40Kh13-Kh12MF1 is Kh12MF1 - "die" steel. It retains its shape well, is quite plastic, wear-resistant and perfectly hardened when not very difficult technological process up to a hardness of 62-64 HRC. For knife and blade steel in general, these are very large values, since the sharpening of the knife in domestic conditions becomes more complicated, the blade becomes brittle, therefore, to achieve acceptable characteristics, industrial tempering of Kh12MF1 steel during the hardening process is a rather complicated operation.

The excellent wear resistance of Kh12MF1 steel is evidenced by the fact that the so-called "reference" gears and dies for wire production are made from it, and the ability to keep its shape under repeated mechanical stress is used in the manufacture of dies and punches for stamping.

The hardness of the Kh12MF1 steel sets a high carbon content.

Composition of Kh12MF1 steel:

Composite steel 40X13-X12MF1, like most Damascus steels, are obtained by multiple forging of a large number of layers (> 150), made up of its future components - "medical" steel grade 40X13 and "die" steel grade X12MF1. During the forging process, the layers are "welded" together, creating a plastic hard composite, excellent for the production of high quality knives and bladed weapons.

Both alloys, from which the 40X13-X12MF1 composite is forged, are classified as stainless steels due to their high chromium content, therefore the final product is also stainless. Steel 40Х13-Х12МФ1 is called "stainless damascus".

An excellent combination of very hard and relatively soft steels creates an amazing effect: a microscopic saw is formed on the knife blade from 40X13-X12MF1, which creates a good cut even when the knife should feel dull.

The technology for the production of steel 40X13-X12MF1 was developed and implemented at ZZOSS (Zlatoust Specialized Weapon Steel Plant), and has been successfully used for the production of bladed weapons for many years.

Do you have any questions about the product?


Hello! My name is Semyon, I am a sales manager at the ZZOSS online store.

I am ready to answer all your questions about the product "Steel for knives and blades brand 40X13-X12MF1 - stainless damascus, application, properties, characteristics." Write or call me if you need advice or want to place an order.

 

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