Introduction to brass grades, properties and uses

Introduction to the performance and uses of brass
grades Brass grades: H62 ordinary brass, H65 ordinary brass, H68 ordinary brass, H70 ordinary brass, H75 ordinary brass, H80 ordinary brass, H85 ordinary brass, H90 ordinary brass, H96 ordinary brass, HA177-2 aluminum brass, HA177-2A aluminum brass, HMn58-2 manganese brass, HPb59-1 lead brass, HSn62-1 tin brass, HSn70-1 tin brass;
H62 ordinary brass: has good mechanical properties, good plasticity in hot state, good plasticity in cold state, good machinability, easy brazing and welding, corrosion resistance, but prone to corrosion cracking. In addition, it is cheap and is a common brass variety that is often used. It is used for various deep drawing and bending parts, such as pins, rivets, washers, nuts, conduits, pressure gauge springs, screens, radiator parts, etc.
H65 ordinary brass: its performance is between H68 and H62, its price is cheaper than H68, it also has higher strength and plasticity, it can withstand cold and hot pressure processing well, and has a tendency to corrode and crack. It is used for small hardware, daily necessities, small springs, screws, rivets and mechanical parts.
H68 ordinary brass: it has extremely good plasticity (the best among brasses) and high strength, good cutting performance, easy welding, non-stable to general corrosion, but easy to crack. It is the most widely used variety among ordinary brass. It is used for complex cold stamping and deep stamping parts, such as radiator shells, conduits, bellows, shells, gaskets, detonators, etc.
H70 ordinary brass: it has extremely good plasticity (the best among brasses) and high strength, good cutting performance, easy welding, non-stable to general corrosion, but easy to crack. It is used for complex cold stamping and deep stamping parts, such as radiator shells, conduits, bellows, shells, gaskets, detonators, etc.
H75 ordinary brass: has quite good mechanical properties, processing properties and corrosion resistance. It can be well processed by hot and cold pressure. It is between H80 and H70 in terms of performance and economy. It is used for low-load corrosion-resistant springs.
H80 ordinary brass: has similar performance to H85, but has higher strength and better plasticity. It has higher corrosion resistance in the atmosphere, fresh water and sea water. It is used for papermaking nets, thin-walled pipes, corrugated pipes and house construction products.
H85 ordinary brass: has high strength, good plasticity, can withstand cold and hot pressure processing well, and has good welding and corrosion resistance. It is used for condensation and heat dissipation pipes, siphons, serpentine pipes, and cooling equipment parts.
H90 ordinary brass: has similar performance to H96, but slightly higher strength than H96, and can be plated with metal and enamel. It is used for water supply and drainage pipes, medals, artworks, water tank belts, and bimetallic strips.
H96 ordinary brass: has higher strength than red copper (but it is the lowest among ordinary brasses), good thermal and electrical conductivity, high corrosion resistance in the atmosphere and in the environment, and good plasticity. It is easy to process cold and hot pressure, easy to weld, forge and tin, and has no tendency to stress corrosion cracking. It is used as conduits, condenser pipes, radiator pipes, radiators, automobile water tank belts, and conductive parts in general machinery manufacturing.
HA177-2 aluminum brass: It is a typical aluminum brass with high strength and hardness, good plasticity, can be press-processed in hot and cold states, has good corrosion resistance to seawater and salt water, and is resistant to impact corrosion, but has a tendency to dezincification and corrosion cracking. It is used as condenser pipes and other corrosion-resistant parts in ships and coastal thermal power plants.
HA177-2A aluminum brass: The performance and composition are similar to HA177-2. The corrosion resistance to seawater is improved by adding a small amount of arsenic and antimony, and the mechanical properties are also improved by adding a small amount of beryllium. The use is the same as HA177-2.
HMn58-2 manganese brass: It has high corrosion resistance in seawater, superheated steam, and chlorides, but has a tendency to corrosion cracking; it has good mechanical properties, low thermal conductivity and electrical conductivity, is easy to be press-processed in hot states, and has acceptable press processability in cold states. It is a widely used brass variety. It is used for important parts working under corrosive conditions and weak current industrial parts.
HPb59-1 lead brass: It is the most widely used lead brass. It is characterized by good machinability, good mechanical properties, ability to withstand cold and hot pressure processing, easy brazing and welding, good stability to general corrosion, but has a tendency to corrosion cracking. It is suitable for various structural parts made by hot stamping and cutting, such as screws, washers, gaskets, bushings, nuts, nozzles, etc.
HSn62-1 tin brass: It has high corrosion resistance in seawater, good mechanical properties, cold brittleness during cold processing, and is only suitable for hot pressing processing. It has good machinability, is easy to weld and braze, but has a tendency to corrosion cracking (seasonal cracking). It is used as ship parts or other parts in contact with seawater or gasoline.
HSn70-1 tin brass: It is a typical tin brass, with high corrosion resistance in the atmosphere, steam, oil and seawater, and good mechanical properties. It has fair machinability, is easy to weld and braze, has good pressure processing properties under cold and hot conditions, and has a tendency to corrosion cracking (seasonal cracking). It is used for corrosion-resistant parts (such as condensers) on seagoing ships, pipes in contact with seawater, steam, and oil, and parts of thermal equipment.

General corrosion characteristics of brass
Brass is a Cu-Zn alloy with Zn as the main alloying element. It is called brass because of its yellow color. According to the type and content of the added alloying elements, brass can be divided into three categories: single-phase brass, complex-phase brass and special brass. When the zinc content is less than 36%, a single-phase α solid solution is formed, so single-phase brass is also called α brass. When the zinc content is 36%-45%, it becomes α+β complex phase brass. When the zinc content is greater than 45%, due to too much β phase, it is brittle and has no practical value. Special brass is based on Cu-Zn, and Sn, Mn, Al, Fe, Ni, Si, Pb and other elements are added.
Brass corrodes very slowly in the atmosphere, and the corrosion rate in pure fresh water is not large (0.0025-0.025mm/year), and it corrodes slightly faster in seawater (0.0075-0.1mm/year). Fluoride in water has little effect on the corrosion of brass, chloride has a greater effect, and iodide has a serious effect. In water containing gases such as O2, CO2, H2S, SO2, NH3, the corrosion rate of brass increases dramatically. It is very easy to corrode in mineral water, especially in water containing Fe2(SO4)3. It corrodes severely in nitric acid and hydrochloric acid, corrodes slowly in sulfuric acid, and is corrosion-resistant in NaOH solution. Brass has better impact corrosion resistance than pure copper.
Special brass has better corrosion resistance than ordinary brass. Adding about 1% Sn to brass can significantly reduce the dezincification corrosion of brass and improve its corrosion resistance in seawater; adding about 2% Pb to brass can increase wear resistance, thereby greatly reducing its corrosion rate in flowing seawater. In order to prevent dezincification corrosion, a small amount of As, Sb, and P (0.02%~0.05%) can also be added; 0.5%~1.0% Mn in naval brass can improve strength and have good corrosion resistance. 12%-18% Ni is used to replace part of Zn in brass containing 65% Cu and 55% Cu. Because of its silvery white color, it is called nickel silver or German silver. This alloy has excellent corrosion resistance in salt, alkali and non-oxidizing acid. At the same time, since a large amount of Ni replaces 2n, there is no dezincification phenomenon. In addition to the above-mentioned corrosion characteristics, brass has two important corrosion forms, namely dezincification corrosion and stress corrosion.