Probably, every person, even the most distant from industry, even at the edge of his ear heard about the outstanding properties of high-speed steel P18. According to rumors, this is a heavy-duty alloy capable of cutting, drilling or otherwise processing steel of any other grade. In addition to strength characteristics, the high-speed 18th steel is highly valued by blacksmiths, manufacturers of household knives and knives. Does steel P18 deserve such an attitude or is everything we know about it just an exaggeration, that is, a folk myth, so to speak? The article will answer this question.
GOST
First you should refer to the available technical documentation. In this case, it will be GOST under the number 19265-73. In it, we are primarily interested in the list of all alloying elements contained in the alloy, and their mass fraction, of course, in percent.
Steel P18 has the following chemical composition.
- Carbon, giving it hardness and strength - from 0.7 to 0.8 percent.
- Manganese and silicon, which increase the wear resistance and strength of steel without reducing the toughness - from 0.2 to 0.5 percent.
- Chrome, which increases corrosion resistance and overall strength, is contained in an amount of 3.8-4.4 percent of the total mass.
- Tungsten is the main alloying component for any high-speed steel, increasing strength, cutting properties and heat resistance. The alloy contains in an amount of 17 to 18.5 percent.
- Vanadium, which increases the strength characteristics of steel, contains from 1–1.4 percent.
- The addition of cobalt in the amount of 0.5 percent of the total mass also positively affects the cutting properties and strength of the alloy.
- Among other things, one percent of molybdenum is added to the composition of the steel , which helps it become even harder and at the same time increase its heat resistance and cutting properties.
- Nickel in the amount of 0.6 percent in the ligature composition is present in order to balance the steel, giving it ductility and elasticity, as well as increase hardenability.
However, even in steel so saturated with alloying elements , there were some “pests” in the form of insignificant impurities of copper — 0.25 percent, phosphorus and sulfur — 0.3 percent each.
Steel P18: material characteristics
Having studied the full list of alloying elements of steel, it is much easier for us to understand the limits of its capabilities. And, as it turned out, P18 steel is really capable of much. Due to the high content of tungsten with the addition of cobalt, molybdenum and vanadium, the alloy is endowed with high density, overall hardness, as well as heat resistance. However, many people know that carbides are more susceptible to failure under load. In this case, manganese, silicon, nickel and a moderate carbon content save P18 steel. Thus, it becomes more balanced and resistant to fracture and wear. It is these qualities that are paramount for steel used in the manufacture of cutting tools for metalworking.
Application
We have already made a reservation that P18 steel is used for the manufacture of cutting tools, but it would be more appropriate to provide you with a, if not a complete, but still a list of products made from this steel. The list contains:
- drills (mainly for metal);
- sweep;
- taps for cutting internal threads;
- dies for cutting external threads;
- cutters for lathes for metal ;
- countersinks;
- broaches;
- cutters.
However, you should be very careful, since P18 is an expensive steel, and it is not always used. So once again follow the markings.
Forging
Steel P18, the characteristics and application of which we have already discussed in detail above, can also be interesting as a material for the manufacture of various household items, in particular knives, chisels, chisels, chisels, in general, anything that is intended to cutting work. And in order to make life easier for blacksmiths and knives, we will examine in detail all the main technological stages of the production of such products.
- Temperature corridor for forging the product - 1 280–900 ° C. However, due to the initial density of the material, steel forges are very problematic. It will take time and effort.
- Hardening will require preliminary heating of the blade to 800 ° C, followed by basic heating to a hardening temperature of 1,280 ° C. P18 is quenched only in oil heated to 200 ° C, after which it cools down in air.
- Vacation is carried out at a temperature of 400 ° C for one hour, but three times. The final hardness of the product will be around 62 units on the Rockwell scale.
Brand Analogs
I would like to leave the last few words in case you suddenly find yourself outside the borders of our vast country, and you urgently need something quick-cutting. In this case, it is better to familiarize yourself with P18 analogues in foreign markets.
- United States - T1.
- Europe - 1.3535 or HS18-0-1.
- Japan - SKH2.
- England - VT1.
- China - W18Cr4V.
This list contains only a small part of the known analogues of the P18th steel. But even it will be enough to find what you need, if necessary.