Brass is binary copper-zinc alloy, also known as common brass, according to the organization can be divided into single brass and two-phase brass. Single brass also known as brass, copper content in 62.4%-100% (wt) . Two-phase brass is (+) brass, the CU content is between 56.6%-62.4% (wt) , the solid solubility of Zn in Cu increases with the decrease of temperature. In addition to aluminum-containing brass, brass generally no heat treatment strengthening effect. Therefore, annealing is often used to improve its cold processing (stamping, drawing, machining) performance. The mechanical properties and cold deformation properties of semi-finished brass after annealing mainly depend on the grain size, the general rule is that the grain size is small and the hardness is high. In addition, large cold deformation, high hardness (cold work hardening) , low annealing temperature, high hardness. After cold deformation annealing, the hardness is low for a long time at the same temperature, and low for a long time at the same temperature.

Brass with low zinc content has little cold work hardening effect, so it needs to refine its grain to obtain higher hardness. Brass containing more than 20% (WT) of Zn exists residual stress after cold deformation. In humid atmosphere (especially the atmosphere containing ammonia and ammonium salt) , mercury and mercury salt solvents, stress corrosion and cracking are easy to occur, so stress relief annealing must be carried out.

The intermediate annealing temperature (c) during the cold working of brass generally needs to be appropriately reduced with the reduction of the effective size (mm) , as listed below:

H96：

560-600（＞5mm） 540-580（1-5mm）

500-540（0.5-1mm）450-500（＜0.5mm）

H90：

650-700（＞5mm） 620-680（1-5mm）

560-620（0.5-1mm）450-560（＜0.5mm）

H80：

650-700（＞5mm） 580-650（1-5mm）

540-600（0.5-1mm）、500-560（＜0.5mm）

H68：

580-650（＞5mm） 540-600（1-5mm）

500-560（0.5-1mm） 440-500（＜0.5）

H62、H59：

650-700（＞5mm） 600-660（1-5mm

520-600（0.5-1mm） 460-530（＜0.5mm）

HFe59-1-1：

600-650（＞5mm） 520-620（1-5mm）

450-550（0.5-1mm） 420-480（＜0.5mm）

HSn70-1：

600-750（＞5mm） 560-620（1-5mm）

520-580（0.5-1mm） 450-500（＜0.5mm）

HSn62-1：

600-650（＞5mm） 550-630（1-5mm）

520-580（0.5-1mm） 500-550（＜0.5mm）

HSn63-3：

600-650（＞5mm） 540-620（1-5mm）

520-600（0.5-1mm） 480-540（＜0.5mm）

HSn59-1：

600-650（＞5mm） 580-630（1-5mm）

550-600（0.5-1mm） 480-550（＜0.5mm）

The annealing temperature (c) of the tube and bar shall be gradually increased with the relative "hard, semi-hard and soft" state before annealing, as follows:

H96 Soft 550-600H80 soft 480-550H68, H62 hard 340-380 semi-hard 400-450HPb59-1, hsn70-1 semi-hard 420-450H60 round rectangular guided wave tube hard 200-250

Bar:

H96 soft 550-620H90, H80, H70 soft 650-720H68 semi-hard 350-400 soft 500-550H62, hsn62-1 semi-hard 400-450H59-1, hfe59-1-1 semi-hard 350-4000hm58-2 semi-hard 320-370

The recrystallization annealing of brass wire needs to increase the annealing temperature (°c) gradually with the three states of "hard, semi-hard and soft" before annealing, and the wire diameters should be adjusted accordingly:

H96、H90、H80：

Line diameter 0.3-0.6 soft390-410

Diameter 0.3-6.0 hard 160-180 soft 390-410

H68：

Wire diameter 0.3-6.0 hard 160-180 half hard 350-370 soft 460-480

H62：

Wire diameter 0.3-1.0 hard 160-180 half hard 160-180 soft 390-410

Diameter 1.1-4.9 hard 160-180 half hard 240-260 soft 390-410

Wire diameter 5.0-6.0 hard 160-180 half hard 260-280 soft 390-410

HPb59-1：

Wire diameter 0.3-6.0 hard 160-250 half hard 330-350 soft 390-430

When AL, NI, FE, SN, SI, MN, PB and other major elements are incorporated into the phase and phase, the relative quantities of the phase and phase change. Brass containing more than 3% AL (wt) can be aged. For example, the heat treatment hardening process of HAl59-3.2 is solid solution at 800 °C and aging at 350-450 °C.

The standard grain size of brass is expressed in terms of average grain size (mm)(see YS/T347-2004"method for determining the average grain size of copper and copper alloys") . Different standard grain size, suitable for different processing methods:

The standard grain size is 0.015mm, suitable for light deformation parts, such as blanking and bending. Standard grain size 0.025mm, suitable for light stamping parts, such as embossing and other convex-concave processing. Standard grain size 0.035 mm, suitable for stamping parts requiring bloom slip. Standard grain size 0.050mm, suitable for deep-drawing parts, such as deep-drawing and bending parts. Standard grain size 0.070mm, suitable for stamping parts of heavy parts. The mechanical properties and uses of brass are listed below:

1, H96, annealed, tensile strength 240MPA, elongation 52% , used for guided wave tube, condenser tube, heat sink, conductive parts. 

2, H90, annealed, tensile strength 260MPA, elongation 44% , used for water tank drainage pipes, resistance caps, medals, statues and so on.

 3, H80, annealed, tensile strength 310MPA, elongation 52% , used for copper mesh, thin-walled pipe, corrugated pipe, building supplies and so on.

 4, H68, annealed, tensile strength 330MPA, elongation 56% , used for all kinds of complex cold stamping, radiator shell, guided wave tube, corrugated tube, etc. . 

5, H62, annealing, tensile strength 360MPA, elongation 49% , used for all kinds of pins, nuts, rivets, washers, guided wave tube, clamp plate, ring parts and radiator parts, sugar industry, shipbuilding industry, paper industry parts.

Tin Brass:

1, HSn70-1, annealed (cold deformation 50%) , tensile strength 350 mpa-60% , tensile strength 700 MPA-4% , for marine condenser tubes.

 2, HSn62-1, annealed, (cold deformation 50%) , tensile strength 400 mpa.elongation 40% , tensile strength 700 mpa.elongation 4% , for ship parts. 

3, HSn60-1, annealed, (cold deformation 50%) , tensile strength 380 mpa-40% , tensile strength 560 MPA-10% , for marine welding parts, electrodes. LEAD BRASS: 1, HPb74-3, annealed (cold deformation 50%) , tensile strength 350 mpa-50% elongation, tensile strength 550 mpa-5% elongation, for automotive and agricultural machinery parts requiring good cutting performance. 2, HPb64-2, annealed (cold deformation 50%) tensile strength 350 mpa-55% elongation, tensile strength 600 mpa-5% , used for clock and automobile industry requirements of good cutting performance parts. 3, HPb63-3, annealed (cold deformation 50%) , tensile strength 350mpa-55% , tensile strength 600pma-5% , used for clock parts requiring excellent cutting performance. 4, HPb60-1, annealed (cold deformation 50%) , tensile strength 370 mpa-45% , tensile strength 670 MPA-4% , for parts with good thermal shock and cutting performance.

ALUMINIUM BRASS:

1, HAl85-0.5, annealed, tensile strength 350MPA, elongation 60% , used for marine condenser tube. 2, HAl77-2, annealed (cold deformation 50%) , tensile strength 400 mpa-55% , tensile strength 650 mpa-12% , for marine condenser tubes. 3, HAl60-1-1, annealed (cold deformation 50%) , tensile strength 450 mpa-45% , tensile strength 750 MPA-8% , used for high strength parts working in seawater. 4, HAl59-3-2, annealed (cold deformation 50%) , tensile strength 380 mpa-50% elongation, tensile strength 650 mpa-15% elongation, used for high strength parts working at room temperature. MANGANESE BRASS: 1, HMN 58-2, annealed (cold deformation 50%) , tensile strength 400 MPAA, elongation 40% ; tensile strength 700 MPAA, elongation 10% , for ships and weak current industrial parts. 2, HMn57-3-1, annealed (cold deformation 50%) , tensile strength 550 MPA25% , tensile strength 700 MPA3% , used for corrosion resistant parts.

IRON BRASS:

1, HFe59-1-1, annealed (cold deformation 50%) , tensile strength 450 mpa-50% , tensile strength 700 MPA-7% , parts and gaskets for friction and seawater corrosion. 2, HFe58-1-1, annealed, tensile strength 450MPA, elongation 10% , used for hot pressing and machining parts with high cutting requirements. NICKEL BRASS: 1, HNi65-5, annealed, tensile strength 380MPA, elongation 65% , used for pressure gauge tubes, condensing tubes, etc. . SILICON BRASS: 1, HSi80-3, annealed, tensile strength 500MPA, elongation 40% , used for steam pipes, water pipe fittings, can replace kicking wear-resistant tin bronze. 2, HSi65-1.5-3, annealed, tensile strength 300MPA, elongation 20% , used for even pipe, water pipe fittings, can replace wear-resistant tin bronze. 

Source: Learn a little heat treatment every day

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