BRASS FITTING

Brass fitting:

Bass is composed of copper and zinc alloy. If it is only the copper, zinc composition of the brass called on ordinary brass. If it is from the above two kinds of elements called on the various special brass alloy. If the lead, tin, manganese, nickel, lead, iron, copper alloy composed of silicon. Brass has strong wear resistance. Special Brass special brass called it high strength, hardness, corrosion-resistant chemical. Also cutting the mechanical properties are more prominent. From the brass pull into a seamless brass, soft, strong wear resistance. Brass seamless tube heat exchanger and condenser can be used for low temperature piping, the Cross-Harbour transport tube.

Manufacturing sheet metal, beams, rods, tubing, such as casting parts. Copper in 62% ~ 68%, plastic-to create pressure equipment. According brass alloy elements contained in the different types, brass brass is divided into ordinary and special brass two. Pressure processing brass called deformation brass. General Organization ordinary brass at room temperature Cu-Zn binary alloy is brass, zinc variation range, so the room temperature organizations were very different. According Cu-Zn binary state diagram (Figure 6), the brass at room temperature three organizations: 35% zinc volume in the following brass, at room temperature microstructure from single-phase solid solution composed of α, α called brass; zinc in the 36% to 46% within the scope of brass, at room temperature by the microstructure (α + β) two-phase component, known as the (α + β) brass (two-phase Brass) ; zinc content in excess of 46 per cent to 50 per cent of the brass, at room temperature microstructure only by β phase, known as β brass. brass fitting pressure-α processing performance of brass (from the H96 and H65) has a good plasticity, can withstand the cold processing, but α brass in the single-phase heat processing, forging and other vulnerable emerging temperature brittle, with the specific temperature range volume containing Zn vary, generally between 200 to 700 ℃.

Therefore, thermal processing temperature should be higher than 700 ℃. Single-phase α Brass temperature brittle zone is the main reason in the Cu-Zn alloy α phase of the region there is a Cu3Zn and orderly Cu9Zn two compounds, in the low-temperature heating in an orderly change to Alloy addition, Alloy in the amount of lead, bismuth and copper forming harmful impurities low melting point eutectic films distributed in the grain boundary, the thermal processing of a rupture between the crystal. Practice shows that, by adding small amount of cerium can be effectively eliminated in the temperature brittle. Brass two-phase (from the H63 and H59), in addition to Alloy Plastic good α phase, but also emerged from the electronic CuZn-based compounds β-solid solution. Β-phase high temperature with high plasticity, and temperature of β ‘phase (orderly solid solution) hard and brittle nature.

Therefore, (α + β) brass should be carried out in the hot forging.brass ball valveZinc is greater than 46% to 50% of the β brass because of hard and brittle, not pressure processing. the mechanical properties of zinc brass because of different mechanical properties are different, Figure 7 is a brass mechanical properties of the zinc vary the curve. For α brass, with the increased volume of zinc, σ b and δ are rising. For (α + β) brass, zinc when volume increased to about 45%, at room temperature strength continues to increase. If further increase the volume of zinc, as Alloy has emerged in the greater fragility of the r (Cu5Zn8 compounds, as the solid solution), the drastic reduction in strength. (Α + β) at room temperature plastic brass were always with the increase in zinc and lower. So zinc in excess of 45% of the copper-zinc