How to identify the quality of brass

Copper identification: Put the copper into a container with dilute hydrochloric acid (or dilute sulfuric acid), and bubbles will appear on the surface of the copper. Put brass into a container containing ferrous sulfate solution, after a period of time, so that the color of the reagent changes, is brass.

Definition: Brass is a copper zinc alloy, it has the chemical properties of copper and zinc. Brass is made of copper and zinc and is called common brass. Copper pipe is commonly used to make valves, pipes, air conditioning internal and external connecting pipes and radiators.

2. To distinguish the three methods of brass, just find out three kinds of chemical reagents can react with zinc: such as ferrous sulfate, dilute hydrochloric acid, dilute sulfuric acid.

3. Measurement of brass purity measurement of brass purity measurement of Archimedes principle to measure the volume and quality of the sample, and then according to the density of copper and zinc density to calculate the copper proportion in brass.

4 main classification: common brass, special brass (other alloy elements added to the common brass in the multiple alloy called brass. Often added elements are lead, tin, aluminum, etc., can also be referred to as lead brass, tin brass, aluminum brass. Use of added alloys. Improve tensile strength and process performance.

The basic classification

1, lead brass

In fact, lead is insoluble in copper and appears as a free particle at the grain boundary. Lead chalcopyrite can be divided into α and (α+β) according to its tissue type. Lead brass can only be processed by cold deformation or hot extrusion because of its great harm to human body and low plasticity at high temperature. Lead brass (α+β) has good high temperature plasticity and can be forged.

2, tin brass

The addition of tin can significantly improve the heat resistance of the alloy, especially its ability to resist seawater corrosion, so tin brass is called "navy brass".

Common tin brass HSN70-1, HSN62-1, HSN60-1 and so on. The former alloy is α alloy with strong plasticity and can be processed by cold and hot pressure. The latter alloy has (α+β) two-phase structure, and a small amount of R phase is often present, and the plasticity is not high at room temperature, so it can only be deformed at high temperature.

3, manganese brass

The solubility of manganese in solid brass is high. The strength and corrosion resistance of brass can be improved obviously by adding 1%~4% manganese, but its plasticity is not decreased.

Manganese copper has the structure of (α+β), and HMN58-2 is commonly used. It has good performance in hot and cold environment.