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.

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).

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.

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.

scholarly journals Resistance of High-Strength Steels to Stress Corrosion Cracking Depending on External Environment pH Factor

2018 ◽  
Vol 20 (3) ◽  
pp. 19-23
Author(s):  
Petr Jonsta ◽  
Irena Vlckova ◽  
Zdenek Jonsta ◽  
Vladimir Tomasek ◽  
Tatana Fenclova
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Temper Embrittlement ◽  
Crack Tip ◽  
High Strength Steels ◽  
High Strength ◽  
Corrosion Cracking ◽  
Localized Corrosion ◽  
Aqueous Environment ◽  
Antimony Electrode

The paper deals with the study of stress corrosion cracking of high-strength steels in an aqueous environment with a varying pH factor ranging from 5.5 to 12.0. Steels were studied after quenching and tempering, one of the steels was prone to temper embrittlement. Single-edge notched pre-cracked specimens were used for the experiments. Changes in the pH factor at the crack tip were measured using an antimony electrode. The pH factor values at the crack tip dropped to 2.0. Steel prone to temper embrittlement showed significantly shorter incubation period and more accelerated development of corrosion process compared to the optimized heat treatment of the second steel. Proneness to intergranular fracture was observed close to the fatigue crack tip. The obtained results expand the existing knowledge about localized corrosion processes leading to the refinement of the stress corrosion cracking model when changing the pH factor on the crack tip.

scholarly journals THE INFLUENCE OF MICROSTRUCTURAL FACTORS AND HEAT TREATMENT ON THE CORROSION RESISTANCE OF REINFORCING STEEL CLASS A 600

2018 ◽  
Vol 22 (2) ◽  
pp. 52-63 ◽  
Author(s):  
N. N. Sergeev ◽  
V. V. Izvol'skiy ◽  
A. N. Sergeev ◽  
S. N. Kutepov ◽  
A. E. Gvozdev ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Corrosion Resistance ◽  
Chemical Composition ◽  
Carbon Content ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Steel Reinforcement ◽  
Reinforcing Steel

Currently, hot rolled bar reinforcement class A600 of low-alloy steels in the delivery condition has a high tendency to this very specific kind of destruction as stress corrosion cracking under tension (SCC). However, there are cases of collapse of pre-stressed concrete structures, in most cases initiated corrosion cracking under stress, put the problem this type of fracture is particularly acute. In stress corrosion cracking cracks occur, the occurrence of which depends not only on the structural state of the material, the type and level of stress, but also on the degree of aggressiveness of the environment in which the operation occurs. In this regard, it is very important to establish how the corrosion resistance of class A600 reinforcing steel varies depending on the change in the chemical composition, microstructure, the level of applied and residual micro-stresses, and various modes of heat treatment. The purpose of this paper is to study the effect of the above factors on the resistance of low-alloyed reinforcing steel class A600 stress corrosion cracking It is shown that the sensitivity of the reinforcement to stress corrosion cracking is largely determined by the chemical composition (mainly carbon content), the type of microstructure and the level of residual micro-stresses. The influence of heat treatment regimes on the corrosion resistance of A600-grade reinforcing steel in nitrates solutions is investigated. It is shown that the use of additional heat treatment (normalization and improvement) increases the corrosion resistance of steel. High corrosion resistance steel reinforcement has only a carbon content at the lower limit of the vintage composition, which is provided by the structure of homogeneous bainite with mechanical properties at the level of strength class A600. With higher mechanical properties, the steel reinforcement has lower corrosion resistance.

scholarly journals Effect of Organizational Evolution on the Stress Corrosion Cracking of the Cr-Co-Ni-Mo Series of Ultra-High Strength Stainless Steel

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 497
Author(s):  
Shuai Tian ◽  
Zhenbao Liu ◽  
Renli Fu ◽  
Chaofang Dong ◽  
Xiaohui Wang
Keyword(s):  
Electron Microscopy ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
High Strength ◽  
Corrosion Cracking ◽  
Holding Time ◽  
Organizational Evolution ◽  
Austenite Content

Different microstructures were obtained under various thermal conditions by adjusting the heat treatment parameters of the Cr-Co-Ni-Mo series of ultra-high strength stainless steel. The effect of organizational evolution on the stress corrosion cracking (SCC) of the Cr-Co-Ni-Mo series of ultra-high strength stainless steel was investigated using potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and other test methods in combination with slow strain rate tensile tests (SSRTs). The results show that the Mo- and Cr-rich clusters and precipitation of the Laves phase reduce the corrosion resistance, while increasing the austenite content can improve the corrosion resistance. The Cr-Co-Ni-Mo series of ultra-high strength stainless steel has a high SCC resistance after quenching at 1080 °C and undergoing deep cooling (DC) treatment at −73 °C. With increasing holding time, the strength of the underaged and peak-aged specimens increases, but the passivation and SCC resistance decreases. At the overaged temperature, the specimen has good SCC resistance after a short holding time, which is attributed to its higher austenite content and lower dislocation density. As a stable hydrogen trap in steel, austenite effectively improves the SCC resistance of steel. However, under the coupled action of hydrogen and stress, martensitic transformation occurs due to the decrease in the lamination energy of austenite, and the weak martensitic interface becomes the preferred location for crack initiation and propagation.

Effect of heat treatment on the susceptibility of high-strength steels to stress-corrosion cracking

1972 ◽  
Vol 5 (5) ◽  
pp. 515-516
Author(s):  
R. K. Melekhov ◽  
M. G. Khitarishvili ◽  
I. I. Vasilenko ◽  
G. V. Karpenko
Keyword(s):  
Heat Treatment ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
High Strength Steels ◽  
High Strength ◽  
Corrosion Cracking

AMBRONZE 413

Alloy Digest ◽  
1969 ◽  
Vol 18 (6) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
Stress Corrosion ◽  
Tensile Properties ◽  
Stress Corrosion Cracking ◽  
Electrical Contact ◽  
Heat Treating ◽  
Corrosion Cracking ◽  
Tin Bronze

Abstract AMBRONZE 413 is a copper-tin bronze recommended for plater's plates and electrical contact springs. It is relatively immune to stress-corrosion cracking. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Cu-201. Producer or source: Anaconda American Brass Company.

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