2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16
An alloy of iron and carbon with a content of the latter of not more than 2, 14% is called steel. The main qualities of steel: strength, ductility, toughness, elasticity, wear resistance and others. The main classification of steels is determined by:
-
steel classification Chemical composition.
- Structural composition.
- The quality of steel or alloy (depending on the amount of harmful impurities and production method).
- The degree of deoxidation.
- Destination.
Chemical composition
Depending on the amount of carbon content in the composition of the alloy, carbon and alloy steel grades are distinguished. The carbon content in both types of steel also determines their marking and GOST mark. Carbon steel classification is divided into:
- Low carbon (less than 0.3% C (carbon) content).
- Medium carbon (0.3 to 0.7% C content).
- High carbon (C content - above 0.7%).
In order to improve the technological characteristics of the alloy, the steel is alloyed. In the alloy is introduced, in addition to the main components and impurities,special chemical elements (nickel, chromium, molybdenum, aluminum, boron, vanadium, thallium, etc.), which provide complex alloying. In turn, the classification of alloy steels highlights:
- Low-alloyed (contains less than 2.5% steel alloying components).
- Medium-alloyed (contain from 2.5 to 10% of steel alloying components).
- High-alloyed (contains above 10% steel alloying components).
Classification of steels by structural composition
Steel that has passed the alloying process is divided into classes according to the structural composition. The structure of the resulting alloy depends on the content of carbon in it, alloying components and the cooling rate after heating to 900 ⁰С. There are five types of structural composition:
- Pearlite alloy.
- Martensitic alloy.
- Austenitic alloy.
- Ferritic alloy.
- Carbide alloy.
Classification of steels by quality
According to the production conditions (smelting method, impurity content), steels and alloys can be divided into several categories:
- Ordinary quality (S(sulphur) content > 0.06%, P(phosphorus) < 0.07%).
- Quality (content of S (sulfur) > 0.04%, P (phosphorus) < 0.35%).
- High quality (S(sulphur) content > 0.025%, P(phosphorus) < 0.025%).
- Extremely high quality (S (Sulfur) content > 0.015%, P (Phosphorus) < 0.025%).
To ordinary quality steelsinclude carbon steels, the cost and technological characteristics of which are significantly inferior to steels of other classes.
According to the chemical composition, both alloyed and carbon steels can be classified as high-quality types. In the production of quality steels, more stringent manufacturing requirements are observed.
Carbon types of steels of ordinary quality and quality are determined by the degree of deoxidation and the nature of solidification as calm, semi-calm and boiling.
High-quality and especially high-quality steels have high technological characteristics, an increased degree of purification from harmful impurities.
Classification of steels by purpose
By purpose, steel is classified into:
- Instrumental.
- Constructional.
- Steel with special properties.
Recommended:
Sectors of the economy: types, classification, management and economics. The main branches of the national economy
Each country has its own economy. It is thanks to industry that the budget is replenished, the necessary goods, products, and raw materials are produced. The degree of development of the state largely depends on the efficiency of the national economy. The higher it is developed, the greater the economic potential of the country and, accordingly, the standard of living of its citizens
Main types of lumber, characteristics, classification and scope
Wood today is one of the most sought-after materials in many areas of human activity. It has a whole range of special features. Existing types of lumber are able to satisfy any needs of any industry. Their properties and classification deserve detailed consideration
What is FEA and what are its main types and forms?
The development of any modern economy is hard to imagine without the activation of its ties with other countries. Since 1991, Russia has abandoned the state monopoly on foreign trade, which means that all firms now know what foreign economic activity is. Today, every enterprise has the right to enter the world market for goods and services, and the state no longer acts as an intermediary between it and foreign partners
Main types and types of business plans, their classification, structure and application in practice
Each business plan is unique, because it is developed for certain specific conditions. But you need to familiarize yourself with the features of various types of business plans in order to understand their key features. Experts recommend doing this before compiling your own similar document
General industrial vibration: classification, types and its interaction
Production vibration: general concept, classification according to various criteria, basic quantitative characteristics. Possible sources of vibration. Evaluation of mechanical vibrations and their impact on human he alth. Instruments for measuring
