Excellent properties when properly heat treated. Blog about sharpening Stainless steel 40x13

One of the most sought-after 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 40x13 steel, 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 marking means. There are a large number of steels in the world, all differ in their properties. And 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 addition to carbon and iron, it contains other active elements. In this case, chromium is contained: this is indicated by the letter X in the marking. Its percentage is 1.3 percent. But the technical characteristics of steel 40x13 depend mainly on the amount of carbon contained in it. In this case, the material contains 0.40 percent of element with serial number 6.

Alloy steel production

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

  1. Purification of iron ore.
  2. Steel smelting.
  3. Introduction of additional additives.

First of all, iron ore is purified: foreign components, mainly sulfur and phosphorus, are removed. This process is carried out in open melting furnaces using out-of-furnace technology. The refining process is the removal of arsenic and non-ferrous metal impurities 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 a steel product. To do this, the raw material in an electric arc furnace is heated to a temperature of 400 to 600 degrees. During melting, iron turns into cast iron, which has an unstable crystal lattice. Through its stabilization, steel is obtained.

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

Specifications

Following the smelting of the alloyed steel grade, the process of quenching and tempering the sample follows. Hardening of the sample is carried out at a temperature of 1100 degrees. After this, it is important to observe gradual tempering, otherwise the sample will be covered with cracks. To prevent this, this event is held at a temperature of 600 degrees.

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

  1. Temporary tensile strength - 1140 MPa.
  2. The conditional yield strength at residual deformation is 910 MPa.
  3. Relative elongation - 12.5 percent per five times the length of the sample.
  4. Impact strength - 12 J /.

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

Application

In industry, steel 40x13 has been widely used. It is mainly used in environments with high humidity. The chromium contained in it enhances the anti-corrosion properties obtained from conventional hardening.

The presented brand has good plasticity indicators: at a temperature of more than 1000 degrees it is easily deformable. This material is actively used in the production of cutting and measuring tools, household items.

The characteristics of steel 40x13 made it possible to use it in the manufacture of machine parts, mainly bearings and compressor parts. The main condition for the use of finished 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 impact on the use of steel

Steel 40x13 GOST has distinctive indicators of corrosion resistance. It is achieved by hardening the product from a temperature at which 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 at a release temperature above 600 degrees.

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

"Hard-worked, heat-treated, polished bars from high-alloy and corrosion-resistant steel. Specifications.";
GOST 5582-75 "Corrosion-resistant, heat-resistant and heat-resistant thin-sheet rolled products. Specifications";
GOST 5632-72 "High-alloy steels and corrosion-resistant, heat-resistant and heat-resistant alloys. Grades";
GOST 5949-75 "Steel and calibrated corrosion-resistant, heat-resistant and heat-resistant. Specifications";
TU 14-1-2186-77;
GOST 4405-75
GOST 14955-77 "Quality round steel with special surface finish. Specifications.";
GOST 2590-2006 "Steel hot-rolled round bars. Assortment.";
GOST 2591-2006 "Hot-rolled square section steel. Assortment.";
GOST 7417-75 "Sizing round steel. Assortment.";
GOST 4405-75 "Hot-rolled and forged strips from tool steel. Assortment.";
GOST 8559-75 "Square calibrated steel. Assortment.";
GOST 8560-78 "Calibrated hexagonal rolled stock. Assortment.";
GOST 1133-71 "Round and square forged steel. Assortment.";
GOST 5632-72 "High-alloy steels and corrosion-resistant, heat-resistant and heat-resistant steels. Grades.";
GOST 103-2006 "Rolled section steel hot-rolled strip. Assortment.";
GOST 5949-75 "Steel and calibrated corrosion-resistant, heat-resistant and heat-resistant. Specifications.";
GOST 2879-2006 "Hot-rolled hexagonal section steel. Assortment.";
TU 14-11-245-88 "High precision shaped steel profiles. Specifications.";
OST 3-1686-90 "Structural steel blanks for mechanical engineering. General specifications.";

The 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 °С


GOST

Product type

Heat treatment mode

σ in , N/mm²

δ5, %

Sheet thin

Grade Ø, ¤ up to 200 mm Calibrated steel

Annealing or tempering

Hardening: 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 °C

δ < 0,2 мм

Mechanical properties at elevated temperatures


t test, °С

σ in , N/mm²

σ 0.2 , N/mm²

δ5, %

KCU, J / cm 2

t test, ° С

σ in , N/mm²

σ 0.2 , N/mm²

δ5, %

KCU, J / cm 2

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

Steel 40X13 (hardening 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 hardening from a temperature that ensures complete dissolution of carbides. An increase in 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 somewhat lower than that of 30X13 steel. A decrease in corrosion resistance is observed when tempering up to 600°C, then some increase occurs. However, corrosion resistance does not reach the level that both steels have in the hardened or low-stressed state.
Thus, it is advisable to use steels 30X13 and 40X13 either after thermal 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.

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 hardening 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 residual austenite.
The tempering of both grades of hardened steel 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 °С; A c3 \u003d 860-880 ° С; МН = 270 °С; MK = 80 °С.

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 fast heating and cooling rates. In this regard, when heated for hot deformation, slow heating up to 830 ° C is used, and after deformation, slow cooling in a foot, sand or 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 810–880 °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 a given hardness and corrosion resistance. For steels used for the manufacture of surgical instruments, stepwise hardening from 1020-1040 °C is recommended, followed by cooling in alkali at 350 °C in order to reduce warpage and improve elastic properties.

© The use of materials from the site is possible only with the permission of LLC "LASMET"

Any steel has certain properties that are unique to a particular brand. And metallurgists are trying to make every effort to obtain the highest and highest 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 sharpened more easily than one that is made of a more rigid one. BUT solid steel, on the contrary, is highly resistant to mechanical stress.

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

The quality of a knife may not always depend on a specific steel grade. plays a big role here high-quality heat treatment of the product. The most popular steel for the manufacture of knives is steel 40x13. 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 features due to a complex technological process, which involves special hardening. As a result of this procedure, complete dissolution of the carbide, which provides anti-corrosion protection of the material. One of the reasons for the decrease in resistance to the development of corrosion is the reduced content of chromium in the carbide or the decrease in the melting point of steel to 600 degrees. But, if the technological process is provided correctly, then this should not happen.

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

Constituent elements after hardening

After the steel has passed the quenching 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 steel composition. When the melting temperature drops to 450-550 degrees there is a secondary hardness of the material, which occurs as a result of the release 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 of this steel are excellent for household use, as they do not rust under any circumstances, are easy to sharpen and are easy to use and maintain. 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 food use.

Besides, steel 40x13 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 disadvantage of products made from such steel is such a factor as instability to aggressive environments and high temperature conditions. Therefore, this type of steel is forbidden to be used for welding.

What reviews do steel products 40x13 use

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

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

It is worth noting that products made of steel material do not require any special care at all, except for sharpening. But with steel 40x13 careful handling is required because the blades of the knives are very flexible. For example, you can not use such a knife to work with hard surfaces.

Especially popular is a manicure tool made of a material such as steel 40x13. Due to their hardness, the tweezers handle the cuticle well. In this case, do not sharpen the tool often. And its constant use does not lead to deformation of the product.

Particularly pleased 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 steel 40x13, you must remember that you need to treat things carefully. Knife blades do not like to be stored in damp and very humid conditions. Small dots of rust may appear on them, which, of course, will disappear after sharpening. But, it is better to avoid such oversights.

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

Elena, Orel

I have been a nail technician 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 tweezers for trimming the cuticles, made of steel 40x13. The material is quite durable, remains sharp for a long time, does not deform when sharpened.

Svetlana, Yekaterinburg

On the market they offered to buy a bearing for a bicycle made of steel 40x13. Was very satisfied. Turned out to be pretty solid and good quality. Highly recommend!

Any material, including steel, has certain properties that are unique to it. Specialists involved in the development of new steel grades make every effort to obtain optimal properties and characteristics. This fully applies to steel 40X13.

Main characteristics

Steel 40X13, sometimes referred to as 4X13, is classified as a corrosion-resistant, heat-resistant grade. Domestic substitute is steel 30X13. IN 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 aggressive environments.
  • springs, fasteners, shafts and bearings capable of operating in aggressive environments, including at temperatures up to 450 ºC.

This material is obtained in open furnaces. Most often, induction furnaces are used. Steel melting is carried out at temperatures from 850 to 110 degrees Celsius. This mode ensures its complete deformation. To prevent the formation of cracks and other defects, various temperature regimes are used, applied alternately. By the way, for the use of parts from the brand 40X13 in aggressive environments, in order to increase its resistance to corrosion, it is recommended to grind their surface.

Steel of this grade must not be used to create structures using any type of welding.

Analogues

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 grade receives its unique properties, in particular, increased resistance to corrosion, as a result of complex heat treatment.

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

  • carbides;
  • martensites;
  • austenite residues.

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, hardness returns. This is due to the removal of carbides from the steel structure.

Finishing heat treatment (hardening) is carried out at a temperature of 950 - 1000 ºC, followed by cooling in oil or air. Subject to all technological regimes, steel to obtain the required hardness and corrosion resistance.

Technological properties of steel 40X13

Grade 40X13 has good manufacturability when plastic deformation is carried out in a hot state. It is carried out at a temperature of 850 to 1100 ºC. But we must remember that with sudden 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. Upon reaching a temperature of 830 ºC, it is possible to perform rolling or forging. The cooling of the steel must also be carried out slowly.

Steel 40X13 is poorly exposed to cold deformation.

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

The main difficulties that arise when turning and milling steel grade 40X13 are:

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

The fact is that when machining 40x13 cutting, the chips do not break like most carbon steels, but curl in the form of a long chip. 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, at the place of processing, the temperature rises sharply, as a result of which hardening is formed and the surface is unevenly hardened. 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 that disables the cutting tool 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.

The use of steel 40X13

The unique properties of steel of this grade made it possible to use it in the aircraft industry. The fact is that this industry constantly needs materials that have high strength during operation at high temperatures, for example, in an aircraft engine. In addition, in modern aviation technology, parts made from this steel are used in 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 is often called “medical” steel in everyday life, because surgical instruments, in particular scalpels, are made from it. In industry, cutting tools, springs, bearings, and measuring tools are made from 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 a wider application, it makes excellent blades for household, hunting knives and various categories of edged weapons. Knife blades made of 40X13 steel are considered relatively “soft”, therefore they lend themselves well to sharpening, but they also do not hold it for too long. With proper hardening, higher hardness levels (~ 58HRC) can be achieved, but the ductility of the steel suffers greatly.

The composition of steel grade 40X13:

The second component of composite steel 40Kh13-Kh12MF1 is Kh12MF1 - "die" steel. It retains its shape well, is quite ductile, wear-resistant and hardens well with 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 sharpening a knife in domestic conditions becomes more difficult, the blade becomes brittle, therefore, in order 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 it is used to make the so-called "reference" gears and dies for the production of wire, and the ability to keep the shape under repeated mechanical action is used in the manufacture of dies and punches for stamping.

The hardness of Kh12MF1 steel sets a high carbon content.

Composition of steel Kh12MF1:

Composite steel 40X13-X12MF1, like most Damascus steel, is obtained by repeated forging of a large number of layers (> 150), composed of its future components - "medical" steel grade 40X13 and "stamp" steel grade X12MF1. During the forging process, the layers are “welded” together, creating a ductile, hard composite, excellent for the production of high-quality knives and bladed weapons.

Both alloys from which the 40Kh13-Kh12MF1 composite is forged are classified as stainless steels due to the high chromium content, so the final product is also stainless. Steel 40X13-X12MF1 is called "stainless Damascus".

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

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

Have questions about a product?


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

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

 

It might be useful to read: