Easy-cutting lead-free brass alloy for forging and preparation method thereof

Abstract

The invention discloses an easy-cutting lead-free brass alloy for forging and a preparation method thereof. The alloy comprises the following components in percentage by mass: 55-68 percent of copper, 0.1-0.8 percent of bismuth, 0.05-0.3 percent of calcium, 0.05-0.3 percent of lithium, 0.05-0.15 percent of sulfur, 0.001-0.1 percent of aluminum, 0.001-0.05 percent of boron, 0.001-0.08 percent of mixed rare-earth elements (one or more lanthanum, cerium and neodymium) and the balance of zinc and unavoidable impurity. The preparation method comprises the following steps: smelting copper-zinc alloy at 1,150 DEG C-1,300 DEG C; after fusant sprays fire, sequentially adding bismuth and zinc rare-earth medium alloy; after the mixture stands and preserves the temperature for 10 minutes, sequentially adding zinc-calcium medium alloy, copper-sulfur medium alloy, the aluminum, copper-boron medium alloy, the zinc and zinc-lithium medium alloy; stirring and deslagging the mixture; preserving the mixture at 1100 DEG C for 15 minutes-20 minutes and casting the mixture at the casting temperature of 1,000 DEG C-1,050 DEG C; preparing an alloy casting blank; and finally casting and molding the obtained casting blank so as to obtain a part blank. An alloy product obtained by the invention has thin crystalline grain, high hot processing performance as well as favorable cutting performance and is suitable for forging.

Description

technical field [0001] The invention relates to a lead-free brass alloy and a preparation method thereof, in particular to a free-cutting brass alloy with excellent forging performance and a preparation method thereof. The alloy is especially suitable for forging various brass alloy mechanical parts, and is an environmentally friendly green metal material with excellent forging performance. Background technique [0002] Brass has good mechanical properties, good corrosion resistance and low cost, and has a wide range of applications. In order to improve the cutting performance, cold riveting and forging performance of brass, generally 1% to 3% lead is added to the brass material. Commonly used lead brass mainly includes HPb59-1, HPb59-2, HPb63-3 and so on. These lead brasses have excellent machinability and wear resistance, low production cost, good cold and hot workability, can be formed by different processes, and are widely used in various fields, such as electronic and...

AI Technical Summary

Problems solved by technology

The alloy is a low-lead brass alloy. Although the lead content of the alloy is very low, it can meet the current application, but it is obvious that the lead content is still a major disadvantage in the context of increasing attention and advocacy of the application of green and environmentally friendly alloy materials. And the patent does not discuss the plasticity of the alloy

[0007] Chinese patent application 200710066669.0 discloses a high-manganese low-lead brass, which consists of Cu: 45-70%, Mn: 7-30%, Pb: 0.2-4%, X: 0.0001-4, (% by weight), Wherein X is at least one of Fe, As, P, B, Cr, Li, Ni, Sn, Al, and the above-mentioned alloy is a lead-containing high-manganese brass alloy, so it does not meet the requirements of increasingly lead-free, And its forging performance is relatively poor, there are problems in practical application

[0008] Chinese patent application 200510050425.4 discloses a low-antimony bismuth brass alloy and its manufacturing method, which consists of Cu: 55-65%, Bi: 0.3-1.5%, Sb: 0.05-1.0%, B: 0.0002-0.05%, Other elements: 0.2 to 1.2% (weight %). The above alloy is a brass alloy containing bismuth and antimony. Because the alloy contains antimony, the cold workability of the alloy is relatively poor, which affects the subsequent processing performance of the alloy

[0009] Chinese patent application 200610005689.2 discloses a lead-free copper alloy, which consists of Cu: 55.0-89%, Sn: 0.1-10%, Ni: 0.1-2.0%, Si: 0-5.0%, Bi: 0.1-5.0%, Se: 0-3.0%, Al: 0.01-1.0%, P: 0.05-0.15%, RE: 0.01%-0.5% (weight %), the above-mentioned alloy is a brass alloy containing bismuth, and the content of bismuth and selenium is relatively high. High, easy to form defects in the casting process, and the cost is high

[0013] Chinese patent application 02121991.5 discloses a lead-free free-cutting brass alloy material and its manufacturing method. It is a copper-zinc-bismuth alloy. Since the alloy contains 0.5% to 2.2% bismuth, the bismuth content is relatively high , resulting in high cost, poor plasticity, especially the deterioration of high temperature plasticity, so the processing performance is not good