KOZAK saber handmade by master Serhiy Dytyuk, steel 65G - spring steel 52-54 HRC

This is a high-strength structural material that has found wide application in various industries. It has high wear resistance, high temperature resistance and good weldability.

2. Composition and properties of steel 65G

2.1 Chemical composition

2.2 Mechanical properties

• Tensile strength - 650 MPa;
• Temporary resistance - 590 MPa;
• Relative elongation at break - not less than 13%;
• Relative narrowing at break - not less than 50%;
• Brinell hardness - not less than 207 HB.

3. Application of steel 65G

3.1 Construction industry

It is widely used in the construction industry. It is used for the manufacture of structural elements that must withstand high loads, for example, for the production of bridge structures, railway overpasses, as well as for the construction of building foundations.

3.2 Mechanical engineering

It is used in mechanical engineering for the manufacture of parts that can withstand high loads and require increased strength and wear resistance. This steel is widely used in the manufacture of gears, shafts, nuts, bolts and other parts.

3.3 Pipe production

Also used in the production of pipes. It is used to produce pipes that withstand high pressure and require increased strength and wear resistance.

The use of steel 65G and heat treatment of products:  spiral springs, sheet and spring washers are made from steel 65G and other spring steels. Spring steel is used to make springs. The hardness of the springs is within R _c  = 40-50, and spring washers R _c  = 40-48. Upon acceptance, the springs are checked for hardness and elasticity. The test method should, as far as possible, approximate the actual operating conditions of the springs (tension, compression or bending).

Springs made of heat-treated (patented) wire or tape of classes H, P and B undergo additional tempering at a temperature of 250-350 ° to relieve internal stresses that have arisen during their manufacture and to improve the elastic properties of the wire.

Spring release is best done in saltpeter baths for 5-10 minutes, depending on the cross section of the material. When tempering in oil or electric furnaces, special attention should be paid to the uniformity of heating. Vacation time in these furnaces is 20-40 minutes.

Springs made of annealed steel are quenched and tempered. In the case of making springs from wire with a diameter of more than 6 mm, high tempering is carried out before hardening at a temperature of 670-720 ° to eliminate cold hardening resulting from cold winding. Hot-wound springs are normalized before hardening.

For heating for quenching, the springs are placed in chamber furnaces or salt baths heated to the required temperature. To avoid deformation, large springs are heated in a special device.

Small springs are loaded into the oven on a baking sheet. Exposure in the furnace should be the smallest - to prevent oxidation and decarburization. To reduce the residence time in the oven, small springs are placed on a preheated baking sheet. In the absence of a protective atmosphere in the furnace, the springs are packed in an insulating environment, or small amounts of charcoal are thrown into the furnace. Cool the springs in oil. It is not recommended to cool the springs in water to avoid cracking. If hardening in water is necessary, the exposure should be no more than 2-3 seconds. followed by cooling in oil.

Before release, the springs are cleaned of oil by washing in a soda solution or thoroughly rubbing in sawdust. Oil that is not removed from the springs flares up during tempering and changes the tempering conditions, which leads to uneven heating and low hardness. The tempering temperature is 300-420°. The annealing of the extreme turns is carried out in a lead bath.

Large springs are put on pipes before release to eliminate warpage.

Attention should be paid to the surface of the material used for the manufacture of springs. Risks, hair lines and other defects lead to the formation of cracks, and the decarburized layer leads to a decrease in the elastic properties of the spring.

Quite often, anti-corrosion coatings used on a number of springs make them brittle due to the saturation of the metal with hydrogen during pickling and during the coating process. This is especially noticeable on springs made of wire or tape of small cross section. This brittleness, called etching or hydrogen, is eliminated by heating the finished springs in oil, glycerin or an oven at a temperature of 150-180 ° for 1-2 hours.

However, during prolonged etching, the metal is saturated with hydrogen so strongly that the specified temperature does not eliminate brittleness and the springs must be annealed. To avoid deep hydrogenation, springs made of thin wire or tape should not be pickled before coating, but should be sandblasted and heated after coating, as indicated above.

4. Features of the use of steel 65G

4.1 Weldability

It has good weldability. However, when welding, certain rules must be observed in order to avoid possible defects in the weld.

4.2 Processing

It has a high hardness, which can make it difficult to process. To facilitate the machining process, it is recommended to use carbide tools.

4.3 Corrosion resistance

Possesses average corrosion resistance. To increase its corrosion resistance, it is recommended to use protective coatings such as primers or paints.

5. Advantages of using 65G steel

• High strength and wear resistance;
• Good weldability;
• Resistant to high temperatures;
• Wide application in various industries;
• Relatively low cost compared to other high strength materials.