Enhancing the Localized Corrosion Resistance of High Strength 7010 Al-Alloy

2010 ◽  
Vol 138 ◽  
pp. 1-6 ◽  
Author(s):  
M. Bobby Kannan ◽  
V.S. Raja
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Grain Boundary ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Intergranular Corrosion ◽  
High Strength ◽  
Localized Corrosion ◽  
Al Alloy

This paper brings out the developments on heat-treatment and alloying to improve the stress corrosion cracking (SCC) behavior of 7010 Al-alloy. The role of microstructures including the grain boundary precipitates and recystallized grains and the relation of intergranular corrosion (IGC) on the SCC behavior of 7010 Al-alloy have been discussed.

scholarly journals Re-Aging Heat Treatment to Stress Corrosion Cracking Resistance on Al-Zn-Mg-Cu Alloy

2009 ◽  
Vol 6 (2) ◽  
pp. 1
Author(s):  
Rasdi Deraman ◽  
Mohd Rozaiman Aziz ◽  
Yusli Yaakob
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Weight Ratio ◽  
High Strength ◽  
Heat Treatments ◽  
Corrosion Cracking ◽  
Localized Corrosion ◽  
Cu Alloy

The Al-Zn-Mg-Cu alloy is classified as a high strength to weight ratio material and is widely used in the aerospace structures. This alloy is susceptible to severe localized corrosion induced by heat treatment. The objective of this study is to elucidate alternative heat treatment techniques, which reduce the alloys susceptibility to Stress Corrosion Cracking (SCC). A series of different heat treatments have been performed in the Al-Zn-Mg-Cu alloy using cube shaped and C-ring specimens that had been T6- and T7-tempered and undergone Retrogression and Re-aging (RRA) heat treatments. The specimens were exposed to hardness testing, optical testing and immersion testing in a corrosive environment. The effectiveness of the heat treatments was evaluated with respect to improvements in corrosion resistance and the longevity of the Al-Zn-Mg-Cu alloy. The susceptibility of the Al-Zn-Mg-Cu alloy to SCC has been directly related to the precipitation of MgZn2 particles at the grain boundaries. Precipitation hardening of Al-Zn-Mg-Cu alloy increases the hardness of the material, but increases susceptibility to SCC failure. RRA treatment greatly improved the corrosion resistance and longevity of the alloy combined with minimal strength reduction.

Strain-induced martensite effects on transgranular carbide precipitation in type 304 stainless steels

1991 ◽  
Vol 49 ◽  
pp. 604-605
Author(s):  
A.H. Advani ◽  
L.E. Murr ◽  
D. Matlock
Keyword(s):  
Heat Treatment ◽  
Grain Boundary ◽  
Stress Corrosion Cracking ◽  
Stainless Steels ◽  
Deformation Twin ◽  
Austenitic Stainless Steels ◽  
Carbide Precipitation ◽  
Strain Induced Martensite ◽  
Type 304

Thermomechanically induced strain is a key variable producing accelerated carbide precipitation, sensitization and stress corrosion cracking in austenitic stainless steels (SS). Recent work has indicated that higher levels of strain (above 20%) also produce transgranular (TG) carbide precipitation and corrosion simultaneous with the grain boundary phenomenon in 316 SS. Transgranular precipitates were noted to form primarily on deformation twin-fault planes and their intersections in 316 SS.Briant has indicated that TG precipitation in 316 SS is significantly different from 304 SS due to the formation of strain-induced martensite on 304 SS, though an understanding of the role of martensite on the process has not been developed. This study is concerned with evaluating the effects of strain and strain-induced martensite on TG carbide precipitation in 304 SS. The study was performed on samples of a 0.051%C-304 SS deformed to 33% followed by heat treatment at 670°C for 1 h.

ALCOA 7075

Alloy Digest ◽  
1998 ◽  
Vol 47 (7) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
Stress Corrosion ◽  
Tensile Properties ◽  
Stress Corrosion Cracking ◽  
High Strength ◽  
Structural Parts ◽  
7075 Alloy ◽  
Very High

Abstract Alcoa 7075 alloy has very high strength and is used for highly stressed structural parts. The T7351 temper offers improved stress-corrosion cracking resistance. The alloy’s strength level equals or exceeds mild steels. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion resistance as well as machining and surface treatment. Filing Code: AL-350. Producer or source: ALCOA Wire, Rod & Bar Division.

Role of Stress in the Stress Corrosion Cracking of a Mg-Al Alloy

CORROSION ◽  
1973 ◽  
Vol 29 (6) ◽  
pp. 251-260 ◽  
Author(s):  
W. R. WEARMOUTH ◽  
G. P DEAN ◽  
R. N. PARKINS
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Al Alloy

Effect of Trace Element Erbium on Corrosion Resistance Properties of Al-Zn-Mg-Cu Alloy

2009 ◽  
Vol 610-613 ◽  
pp. 663-667 ◽  
Author(s):  
Xu Dong Wang ◽  
Zuo Ren Nie ◽  
Shuang Ping Lin ◽  
Xue Kuan Su ◽  
Ze Bing Xing
Keyword(s):  
Corrosion Resistance ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Intergranular Corrosion ◽  
Corrosion Test ◽  
Optical Microscope ◽  
Corrosion Cracking ◽  
Cracking Resistance ◽  
Cu Alloy ◽  
As Stress

The intergranular corrosion and stress corrosion cracking resistance of Al-Zn-Mg-Cu alloy with trace Er addition were studied by means of such methods as stress corrosion cracking and intergranular corrosion test in GB-T7998-2005 and HB5254-83. The microstructures were observed by optical microscope and scanning electron microscope (SEM). The results show that alloys with trace Er addition have been improved on intergranular corrosion and stress corrosion cracking resistance, but corrosion resistance of alloys can be descending when Er addition exceed 0.4%.

Effect of non-conventional heat treatment of API X60 pipeline steel on corrosion resistance and stress corrosion cracking susceptibility

2019 ◽  
Vol 66 (3) ◽  
pp. 274-285 ◽  
Author(s):  
Luis Ricardo Jacobo ◽  
Rafael Garcia ◽  
Victor Hugo Lopez ◽  
Antonio Contreras
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Strain Rate ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Activation Process ◽  
Content Type ◽  
Heat Treated ◽  
Conventional Heat Treatment

Purpose The purpose of this paper is to study the effect of heat treatment (HT) applied to an API X60 steel in corrosion resistance and stress corrosion cracking (SCC) susceptibility through slow strain rate tests (SSRT) in NS4 solution and congenital water (CW) to assess external and internal SCC, respectively. Design/methodology/approach API X60 steel was heat treated at a temperature of 1,200°C for 30 min followed by water quenching. Specimens from this steel were machined according to NACE TM 198. SSRT were performed in a constant extension rate tests (CERT) machine at room temperature at a strain rate of 1 × 10–6 s–1. For this purpose, a glass cell was used. Corrosion behavior was evaluated through polarization curves (PCs). Findings The SCC index obtained from SSRT indicates that the steel heat treated could be susceptible to SCC in CW and NS4 solution; the mechanism of SCC was hydrogen embrittlement. Thus, CW may promote the SCC phenomenon in pipelines. HT improves the steel corrosion resistance. Higher corrosion rate (CR) was observed when the steel is exposed to CW. The corrosion process in X60 steel shows that the oxidation reaction in the anodic branch corresponds to an activation process, and the cathode branches reveal a diffusion process. Originality/value The purpose of the heat treatment applied to X60 steel was to generate a microstructure of acicular ferrite to improve the corrosion resistance and SCC behavior.

Microstructural Contributions to Stress Corrosion Cracking in High Strength Steels

1982 ◽  
Vol 40 ◽  
pp. 462-463
Author(s):  
R. Padmanabhan ◽  
W. E. Wood
Keyword(s):  
Heat Treatment ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
High Strength Steels ◽  
High Strength ◽  
Heat Treatments ◽  
Corrosion Cracking ◽  
Treatment Conditions ◽  
300M Steel ◽  
Conventional Heat Treatment

The effects of microstructural variables upon stress corrosion cracking resistance of 300M steel in 3.5% NaCl solution have been studied. Table 1 lists KIscc values for three heat treatment conditions. The martensite substructure was predominantly twinned plates for conventional heat treatment and dislocated laths for both high temperature and step heat treatments. A typical twinned region observed in the conventional heat treatment is shown in Fig. 1. Such twinned regions were less frequent in the other heat treatments. Both cementite and epsilon carbide were seen in all cases, as illustrated in Figs. 2 and 3 for conventional heat treatment. Epsilon carbide was usually observed within large grain boundary nucleated laths (autotempered martensite), with definite habit planes and growth directions. The formation of such laths have been discussed previously. Retained austenite, mostly in the form of interlath films, was observed in all cases with increased amounts present in coarser grained structures (Fig. 4).

Sign in / Sign up

Export Citation Format

Share Document