CAJ | 학술논문

采用静态腐蚀、XRD、SEM、EDS和XPS,研究了250 ℃时效4 h和70%冷变形+200 ℃时效4 h两种硬化状态下的925Ag75Cu与925Ag40Cu35Zn合金在37 ℃人造汗液和室温H_2S气氛中的腐蚀与变色行为.结果表明,这两种925银合金在37 ℃人造汗液中的腐蚀变色是由Cl~-和OH~-离子引起的,但925Ag40Cu35Zn合金的变色过程明显比925Ag75Cu合金缓慢,腐蚀过程中产生的白色AgCl和灰黑色Ag_2O难以在其表面沉积而形成灰黑色腐蚀膜.这两种925银合金在室温H2S气氛中的腐蚀变色是由S~(2-)引起的,但925Ag40Cu35Zn合金的腐蚀变色过程明显比925Ag75Cu合金缓慢,这是由于腐蚀过程中白色ZnS最先形成,从而延缓了灰黑色 Ag_2S和黑色Cu_2S的形成.
채용정태부식、XRD、SEM、EDS화XPS,연구료250 ℃시효4 h화70%랭변형+200 ℃시효4 h량충경화상태하적925Ag75Cu여925Ag40Cu35Zn합금재37 ℃인조한액화실온H_2S기분중적부식여변색행위.결과표명,저량충925은합금재37 ℃인조한액중적부식변색시유Cl~-화OH~-리자인기적,단925Ag40Cu35Zn합금적변색과정명현비925Ag75Cu합금완만,부식과정중산생적백색AgCl화회흑색Ag_2O난이재기표면침적이형성회흑색부식막.저량충925은합금재실온H2S기분중적부식변색시유S~(2-)인기적,단925Ag40Cu35Zn합금적부식변색과정명현비925Ag75Cu합금완만,저시유우부식과정중백색ZnS최선형성,종이연완료회흑색 Ag_2S화흑색Cu_2S적형성.
The purpose of this paper is to investigate the corrosion and the tarnish behaviour of 925Ag75Cu and 925Ag40Cu35Zn alloys in synthetic sweat at 37℃ and H_2S atmosphere at room temperature. The alloys were in two hardening states, viz., aging at 250 ℃ for 4 h and 70 % cold rolling + aging at 200 ℃ for 4 h, and tested by means of static corrosion, examined by XRD, SEM, EDS and XPS. The results show the corrosion and the tarnish in synthetic sweat at 37 ℃ of these two 925Ag alloys are induced by Cl~- and OH~- anions. The tarnish of 925Ag40Cu35Zn alloy is much slower than that of 925Ag75Cu alloy, and the white AgCl and the grayish black Ag_2O produced by corrosion are difficult to deposit on the surface of 925Ag40Cu35Zn alloy resulting in grayish black corrosion film. The corrosion and the tarnish in H_2S atmosphere at room temperature of these two 925Ag alloys are induced by S~(2-) anion. The corrosion and the tarnish of 925Ag40Cu35Zn alloy are much slower than 925Ag75Cu alloy. This is because Zn in 925Ag40Cu35Zn alloy reacts earliest with H_2S to form white ZnS, which significantly retards the reaction between Ag or/and Cu and H_2S to form grayish black Ag_2S and black Cu_2S.