Representation method of steel grade in China (III) : high quality carbon structural steel and high quality carbon spring steel

Representation method of steel grade in China (III) : high quality carbon structural steel and high quality carbon spring steel

High quality carbon structural steel adopts two Arabic numerals (the average carbon content is expressed in tens of thousands) or Arabic numerals and element symbols to form a brand. ① For, rimmed steel and semi killed steel, the symbols "F" and "B" shall be added at the end of the grade respectively. For example, the grade of rimmed steel with an average carbon content of 0.08% is expressed as "08F"; The grade of semi killed steel with an average carbon content of 0.10% is expressed as "10B". ② . killed steel (s and P ≤ 0.035% respectively) is generally not…
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Representation method of steel grade in China (II): Carbon structural steel and low alloy high strength structural steel

Representation method of steel grade in China (II): Carbon structural steel and low alloy high strength structural steel

Carbon structural steel and low-alloy high-strength structural steel are usually divided into general steel and special steel. The brand representation method is composed of the Chinese phonetic alphabet of the yield point or yield strength of the steel, the value of the yield point or yield strength, the quality grade of the steel, and the deoxidation degree of the steel, which is actually composed of four parts. ① The Pinyin letter "Q" representing the yield point is used for general structural steel. The yield point value (unit: MPa), quality grade (a, B, C, D, e), deoxidation method (F, B, Z,…
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Representation method of steel grade in China (I): Overview

Representation method of steel grade in China (I): Overview

The designation of steel products in China is generally expressed by the combination of Chinese Pinyin letters, chemical element symbols and Arabic numerals. Namely: ① Chemical elements in steel grades are represented by international chemical symbols, such as Si, Mn, Cr, etc. Mixed rare earth elements are represented by "re" (or "XT"). ② Product name, purpose, smelting and pouring method, etc. are generally represented by abbreviations of Chinese pinyin, ③ The content (%) of main chemical elements in steel is expressed in Arabic numerals. When the Chinese phonetic alphabet is used to represent the product name, purpose, characteristics and process…
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Put an end to fake goods and use a few tricks to identify stainless steel

Put an end to fake goods and use a few tricks to identify stainless steel

When the steel type (No.) is unknown, we can determine whether it is stainless steel and what kind of stainless steel it belongs to with the help of simple instruments and senses according to the inherent physical and chemical properties of commodities (including whole materials, surplus materials, waste materials and other objects). It should be pointed out that the sensory identification can not distinguish the specific steel (type) number, but can basically distinguish three categories: chromium stainless steel, chromium nickel stainless steel (SUS304, 304) and chromium manganese nitrogen stainless steel (200 Series). The identification methods are as follows: 1. Color…
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New materials can solve the problem of 3000 ℃ high temperature in supersonic flight

New materials can solve the problem of 3000 ℃ high temperature in supersonic flight

As we know, the speed of sound refers to the speed of sound. The standard speed is to test the speed of sound propagation in the air at the sea level of 15 ℃ (the speed is different in water or other media). The speed of sonic sound in air at 15 ℃ is 340 meters per second, about 1224 kilometers per hour. Supersonic speed refers to the state that the speed is greater than 340 meters per second. The speed less than 340 meters per second is called subsonic speed. The speed equal to 340 meters per second is…
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How to correctly select the most appropriate 3D printing materials?

How to correctly select the most appropriate 3D printing materials?

Traditional manufacturing machines cannot easily integrate a variety of raw materials in the process of cutting or mold forming. With the development of multi-material 3D printing technology, we have the ability to integrate different raw materials. Raw materials that cannot be mixed before will form new materials after mixing. These materials have a wide variety of colors and unique properties or functions. When using 3D printing for the first time, there are various processes and materials to choose, so which process and materials should we choose? There are usually the following considerations: cost, appearance, details, mechanical properties, mechanical properties, chemical…
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Grade of titanium and titanium alloy and classification of metallographic structure after annealing

Grade of titanium and titanium alloy and classification of metallographic structure after annealing

Classification of titanium alloys according to the data, there are many classification methods. The more common one is to classify according to the metallographic structure after annealing: 1. After annealing, the basic structure is a phase, which is called type a titanium alloy; 2. After annealing, the basic structure is A+B, but mainly a phase, which is called near A-type alloy; 3. After annealing, the basic phase A+B is similar, which is called A+B alloy. It can also be called a equiaxed + B transformation or a primary equiaxed + B transformation or a primary equiaxed + a widmanstatten +…
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From history to application, understand the past and present life of engineering plastics

From history to application, understand the past and present life of engineering plastics

1、 What is engineering plastics? Engineering plastics are plastics that can be used as engineering materials and replace metals to make machine parts. Engineering plastics have excellent comprehensive properties, high rigidity, low creep, high mechanical strength, good heat resistance and good electrical insulation. They can be used for a long time in harsh chemical and physical environments. They can replace metals as engineering structural materials, but the price is expensive and the output is small. 2、 Classification of Engineering Plastics: Engineering plastics can be divided into general engineering plastics and special engineering plastics. The former mainly includes polyamide, polycarbonate, polyformaldehyde,…
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