Metal Grade Identification
Project Introduction
Metal grade identification is a process of analyzing the metal elements after confirming the composition and proportion of the sample by joint analysis or chemical analysis, and judging whether it meets the standard requirements by comparing the product standard requirements corresponding to the material grade provided.
Metal material grade identification method mainly uses direct reading spectrometer, inductively coupled plasma atomic emission spectrometer (ICP-OES), inductively coupled plasma mass spectrometer (ICP-MS), carbon sulfur analyzer, oxygen and nitrogen analyzer and other precision instruments to analyze the chemical elements in the metal material, so as to identify its possible material grade.

Metal Grade Identification

Identification Significance
By analyzing the elements and components of the metal, the analyzed data is compared with the standard chemical composition of the grade, so as to determine which metal grade it belongs to. The brand can reflect the type, chemical composition or mechanical properties of the material, etc., and plays a vital role in the quality control of the company's products:
① It is conducive to understanding the causes of the performance of metal materials;
② It is conducive to the reasonable selection of metal material processing methods, heat treatment methods and equipment;
③ It is conducive to the economical, safe and reasonable application of metal materials, avoiding the occurrence of huge losses caused by the use of non-standard materials.
Brand identification range
Metal brands: stainless steel, 304 stainless steel, 316 stainless steel, steel, aluminum alloy, mold steel, carbon steel, ductile iron, ferrite, tungsten steel, carbon structural steel, spring steel, ferrosilicon, heat-resistant steel, titanium alloy, magnesium alloy, copper alloy, etc.

What are the common metal/alloy brand identifications?
① Stainless steel composition analysis and stainless steel brand identification
Such as 304, 304L, 316, 316L, 201, 202, 420, 430 and other stainless steel analysis;
Determination of carbon (C), silicon (Si), manganese (Mn), phosphorus (P), sulfur (S), nickel (Ni), chromium (Cr), molybdenum (Mo), copper (Cu) and other elements.
②Analysis of other iron-based alloy components.
Cast iron, carbon steel, structural steel, spring steel, tool steel, bearing steel, mold steel, galvanized sheet, free-cutting steel, etc.
③Full component analysis and brand identification of non-ferrous metal alloys.
Copper-based alloys (pure copper, brass, nickel silver, bronze, etc.); aluminum-based alloys (deformed aluminum, cast aluminum, pure aluminum, etc.); magnesium-based alloys (magnesium aluminum zinc, magnesium aluminum silicon, etc.); nickel-based alloys (high temperature alloys, precision alloys, etc.); titanium-based alloys (pure titanium, TA1, TB2, TC4, etc.); tin-based alloys (pure tin, lead-tin alloy 6337/6040, lead-free solder SAC0307/SAC305, etc.); zinc-based alloys (pure zinc, zinc-aluminum alloy, etc.).
④ Other alloy materials.
Cemented carbide (tungsten-based, tungsten carbide-based, cobalt-based, etc.); contact materials (silver tungsten, copper tungsten, silver tungsten carbide, etc.).
Reference Standards
National System Standards for Metal Grade Identification
GB——National Standard
GB/T——Recommended National Standard
ISO——International Organization for Standardization
EN——European Standard
ASTM——American Society for Testing and Materials
JIS——Japanese Industrial Standard
Different countries, continents and international organizations have their own independent metal and alloy grade systems, which generally use numbers or letters to indicate a metal.

① In some cases, these letters and numbers can directly indicate the chemical composition and mechanical properties of the metal. For example, spring steel with an average carbon, silicon and manganese content of 0.60%, 1.75% and 0.75% respectively is indicated as "60Si2Mn". For high-quality spring steel, the symbol "A" is added to the end of the grade, and its grade is indicated as "60Si2MnA".
② In other cases, letters and numbers are only arranged in a certain order and do not directly reflect the specific composition or performance of the metal. It is necessary to indirectly understand the details of its composition and performance based on the corresponding standards, such as: ADC6, ADC12, A380.1 (all cast aluminum), TA4, TB4, TC4 (all titanium alloys).

Metal grade identification standards:

GB/T 221-2008 Steel product grade designation

GB/T 3620.1-2016 Titanium and titanium alloy grades and chemical composition

GB/T 4309-2009 Powder metallurgy material classification and grade designation

GB/T 5153-2016 Deformed magnesium and magnesium alloy grades and chemical composition

GB/T 5231-2012 Processed copper and copper alloy grades and chemical composition

GB/T 5612-2008 Cast iron grade designation

GB/T 5613-2014 Cast steel grade designation

GB/T 7738-2008 Ferroalloy product grade designation

GB/T 8063-2017 Cast nonferrous metals and their alloy grades designation

GB/T 14844-1993 Semiconductor material grade designation

GB/T 14992-2005 Classification and designation of high temperature alloys and intermetallic compound high temperature materials

GB/T 15007-2017 Corrosion resistant alloy grades

GB/T 15018-1994 Precision alloy grades

GB/T 15019-2017 Classification and designation of rapidly quenched metals

GB/T 16474-2011 Deformed aluminum and aluminum alloy grade designation

GB/T 17107-1997 Structural steel grades and mechanical properties for forgings

GB/T 17616-2013 Unified digital code system for steel and alloy grades

GB/T 17803-2015 Rare earth product grade designation

GB/T 18035-2000 Precious metals and their alloy grade designation

GB/T 18376.1-2008 Cemented carbide grades Part 1: Cemented carbide grades for cutting tools

GB/T 18376.2-2014 Cemented carbide grades Part 2: Cemented carbide grades for geological and mining tools

GB/T 18376.3-2015 Cemented carbide grades Part 3: Cemented carbide grades for wear-resistant parts

GB/T 20878-2007 Stainless steel and heat-resistant steel grades and chemical composition

GB/T 26314-2010 Zirconium and zirconium alloy grades and chemical composition

GB/T 27675-2011 Aluminum and aluminum alloy composite plates, strips, foils grade representation

GB/T 29091-2012 Copper and copper alloy grades and codes

GB/T 29091-2012 Copper and copper alloy grades and codes

GOST 613-1979 Casting tin bronze brand

GOST 1412-1985 Cast iron containing flake graphite for castings: brand

How to distinguish metals of different brands?
Under the same system, different brands of metals or alloy materials mean that the elements and components contained in them are different, and the performance reflected is also different.
Taking stainless steel as an example, 304 and 202 are both American standard brands. The difference between the two is:
①304 is a universal stainless steel. Common marking methods in the market include 06Cr19Ni10 and SUS304. Among them, 06Cr19Ni10 generally indicates national standard production, 304 generally indicates American standard production, and SUS304 indicates Japanese standard production.
②202 stainless steel is one of the 200 series stainless steels. The national standard brand is 1Cr18Mn8Ni5N and the Japanese brand is SUS202.
③They are all austenitic stainless steels. 202 uses Mn and N to replace part of nickel, thus obtaining good mechanical properties and corrosion resistance. It is a new type of stainless steel that saves nickel. 202 has higher room temperature strength than 304 and has better oxidation resistance and medium temperature strength below 800℃.
Experienced practitioners can use the method of quick identification to observe the sparks, color codes, fractures, sound and other aspects of the material to judge the brand of the metal at the site of use, but this method is limited to simple judgment. To truly distinguish the quality of the material and identify which brand the material belongs to, it is necessary to obtain the content of each element through component analysis of the material.

Will there be differences in metals/alloys under the same brand?
(1) The different methods of expressing the grade of metal materials under the same brand represent different components or properties.
For example: Q345 steel of the same brand is divided into: Q345A, Q345B, Q345C, Q345D, Q345E according to quality grade. It represents the different impact temperatures of different grades of steel.
(2) There will be differences between different batches of metal materials of the same grade and brand. The composition of the same grade is only a range, not fixed, so the fluctuation of the composition will inevitably cause differences in the distribution of the second phase, and the hardness will inevitably be different. However, if the same batch of materials is used and the same part is taken, the quality is roughly the same.