316 stainless steel chloride cracking

Stainless steel 316 and 316l grade 316 is the standard molybdenumbearing grade, second inoverall volume production to 304 amongst the austenitic stainless steels. Type 304 stainless steel showed extensive tgscc in solution annealed condition in 144 h exposure tests. Cl2 chlorine is a very potent oxidizer reason it kills bacteria and therefore high levels of chlorine may accelerate chloride corrosion of stainless steels. One known exception is highly oxidizing acids such as nitric acid to which the molybdenum.

Reference is often made to stainless steel in the singular sense as if it were one material. Chloride stress corrosion cracking in austenitic stainless steel. Higher naoh concentrations and exposure temperatures resulted in a reduced stability of the electrochemical passivity domain. In case of duplex and stainless steel 316, there is no clear winner. Type 304 stainless steel an overview sciencedirect topics. Fourpoint bend testing on parent and welded dualcertified 316316l stainless steel, to iso 151563. These range from kitchen appliances to bridges and buildings. Selection of stainless steels for handling chlorine. The chemical composition and mechanical properties of the gauge cover alloy are shown in table 3, table 4, indicating 316 ss stainless steel. These stainless steel grades alloys can be hardened by heat treatment but have poor resistance to co rrosion.

Certain austenitic stainless steels and aluminium alloys crack in the presence of chlorides. The typical crack morphology for chloride stress corrosion cracking consists of branched transgranular cracks. The gauge cover alloy was type aisi 316 stainless steel. While fluoride is more abundant than chloride in crustal rocks, fluoride is mainly. Grade 316 has virtually the same mechanical, physical and fabrication characteristics as 304 with better corrosion resistance, particularly to pitting corrosion in chloride environments. Chloride stress corrosion involves selective attack of a metal along its grain boundaries. Effects of chloride and oxygen on stress corrosion cracking of cold worked 316316l austenitic stainless steel in high temperature water article in corrosion science 110 april 2016 with reads. Failures have been reported in environments with as little as 10 ppm chlorides. They are subject to both uniform and nonuniform attack in seawater. The resistance to localized corrosion of stainless steels in 20,000,100,000 and 200,000 ppm clsodium chloride solutions was investigated at 90c. All three families of the highperformance stainless steels will deliver a wide range of resistance to chloride pitting and stress corrosion cracking superior to that of types 304 and 316. If this is a potable water as described,there is no reason to consider anything but carbon or galvanized steel. Pdf chloride induced stress corrosion cracking of type 304. Another way to look at alloy performance in resistance to stress corrosion cracking, is to consider the temperature at which scc begins.

Initiation strain for chlorideinduced stress corrosion. How to reduce the risk of stress corrosion cracking scc the risk of stress corrosion cracking scc can be minimized through plant and equipment design. Chloride stress corrosion cracking clscc is one the most common reasons why austenitic stainless steel pipework and vessels deteriorate in the chemical processing and petrochemical industries. What is the maximum chloride in ppm that can be allowed in. The cracking threshold of a 6mo super austenitic stainless steel uns n08367 immersed in oxygenbearing neutral chloride solutions is shown in figure 3.

The duplex stainless steels were developed to exhibit comparable general corrosion resistance as 316ss, but with reduced susceptibility to chloride stress. Localized corrosion and stress corrosion cracking of stainless steels. Apr 28, 2016 the cracking threshold of a 6mo super austenitic stainless steel uns n08367 immersed in oxygenbearing neutral chloride solutions is shown in figure 3. Type 304 stainless steel is highly susceptible to scc in chloride solution as demonstrated by the results of exposure of constant strain samples kain 1997, kain et al. Alloys 316, 316l, and 317l are more resistant to atmospheric and other mild types of corrosion than the 188 stainless steel. Figure 1 shows the cracking that occurred on a 6mo super austenitic stainless steel n08367 exposed to 0. Corrosion behaviour of type 316l stainless steel in hot. This limits the usefulness of austenitic stainless steel for containing water with higher than a few ppm content of chlorides at temperatures above 50 c. Stainless steel grades 400 series this group of alloys are magnetic and have a martensitic structure. High performance stainless steels nickel institute. Handout for participants in scc expert panel discussion. It is found that the stress vs timetofailure curves for both alloys are divided into three regions that are dominated by. The higher nickel and molybdenum content in this grade allows it to demonstrate better overall corrosion resistant properties than 304, especially with regard to pitting and crevice corrosion in chloride environments. The basic alloy contains 11% chromium and 1% manganese.

Since pricing and corrosion resistance are both equally important when deciding a grade for a particular selection. Chloride stress corrosion cracking clscc is one of the most common. There can be a risk of stress corrosion cracking scc attack at higher temperatures, which is common to both the 304 and. Alloy 316 316l is molybdenumbearing austenitic stainless steel. Chloride stress corrosion cracking ssina specialty steel. The most common type of stress corrosion cracking in stainless steels occurs in chloride environments, which will be the focus of this discussion. Selection of stainless steels for handling chlorine cl2. Effects of chloride and oxygen on stress corrosion cracking of cold worked 316316l austenitic stainless steel in high temperature water article in corrosion science. Summary of available data for estimating chlorideinduced scc.

Stainless steel grade 316 is the second most commonly used stainless steel. Chloridechlorine levels and stainless steel alloy selection. Higher naoh concentrations and exposure temperatures resulted in a reduced stability of the. Both 304 and 316 stainless steel types are resistant to a wide range of concentration and temperature. Grade 316 uns s31600 is the second most popular grade in the stainless steel family. Hi everybody, today, i would like to show my case study to you. For example, chloride stress corrosion cracking of austenitic stainless steel has been experienced in hotwater jacketed pipes carrying molten chocolate in the food industry. Stress corrosion cracking of an austenitic stainless steel in. Scc is often associated with chlorides, but can also occur with caustics and other corrosive media. The temperature thresholds are well above the 212f 100c range, indicating that exposures to atmospheric boiling in neutral chloride solutions are very unlikely to produce cracking. The corrosion behaviour of type 316l stainless steel in aqueous 3050 wt%. It requires a susceptible material and, depending on the material, sufficient levels of.

Duplex stainless steel comparison to stainless steel 316l. The mineral oil tube failed after being in service for nearly 10 years. It is an austenitic, corrosion resistant steel with excellent strength, toughness, fabrication characteristics and weldability. The resistance of types 304 and 316 stainless steels to. Olaseinde, comparative study of the effect of temperature on the corrosion behavior of 2205 duplex stainless steel and 316 austenitic stainless steel in acidic chloride environment, advances in materials physics and chemistry 5, 185 190 2015. The micrograph below x300 illustrates scc in a 316 stainless steel chemical processing piping system.

The effects of chloride content, oxygen content and solution ph were studied on test coupons with and without welds and on ubend specimens. The low carbon version, 316l, may be required for full corrosion resistance when thicker sections. On the stress corrosion cracking and hydrogen embrittlement. Chloride stress corrosion cracking scc of type 304 and 304l austenitic stainless steels ss was studied by a constant load method in air at a temperature of 353 k with relative humidity rh of.

Influence of high temperature on corrosion behavior of 304. Chlorideinduced stress corrosion cracking of 316 stainless steel oil tube hi everybody, today, i would like to show my case study to you. A precursor of stress corrosion cracking in chloridebearing environments is pitting corrosion, occurring if the stainless steel is not sufficiently resistant to pitting. Corrosion of stainless steel in sodium chloride brine. Effects of chloride and oxygen on stress corrosion cracking. Chloride stress corrosion cracking and 316 stainless steel. Whenever stainless steel is exposed to chloride concentrations and stress levels, chloride stress corrosion cracking cscc can occur. If the cl is present as hcl you have a problem that 316 wont solve.

Cscc can attack highly resistant austenitic stainless steel. Chlorideinduced stress corrosion cracking of 316 stainless steel oil tube. The addition of 2% molybdenum provides greater resistance to acids and to localized corrosion caused by chloride ions. Chloride corrosion of carbon steel pipe engineering. Stress corrosion cracking facts and how to reduce the. The results indicate that pressure memory gauge cover failed due to chloride stress corrosion cracking clscc. The stress corrosion cracking of type 316 stainless steel in. Below 80 degc they can be considered resistant to any concentration of sodium hydroxide, up to the limit of solubility. Both of type 304 and type 316 stainless steels showed quite similar. The low carbon version, 316l, may be required for full corrosion resistance when thicker sections are welded. It can be detrimental to austenitic stainless steels, one of the main reasons these steels are not considered a cureall for corrosion problems. Scc of the 300 series stainless steels is classically transgranular. While no stainless steel can be completely immune, swageloks alloy 316 stainless steel fittings have performed exceptionally well in testing. If you you have temperatures above 150f,you could have stress corrosion cracking of 316 although unlikely below 200 f.

Pdf chloride induced stress corrosion cracking of type. Stress corrosion cracking of aisi 304 and aisi 316. The second most common austenitic stainless steel is type 316. Chloride stress corrosion cracking is a localized corrosion mechanism like pitting and crevice corrosion. Oct 21, 2019 chloride stress corrosion cracking cscc is a type of intergranular corrosion. The level of chlorides required to produce cracking is relatively low. During investigation many branched cracks were observed on the external surface of the gauge cover grown from the pits perpendicular to the cylinder axis. The 316 alloy is a molybdenumbearing austenitic stainless steel that contains 18% chromium, 8% nickel, and 23% molybdenum. Stainless steels 304l and 316l exhibit pitting in iodine solutions or solutions.

It occurs in austenitic stainless steel under tensile stress in the presence of oxygen, chloride ions and high temperature. Design guidelines for the selection and use of stainless steel nidl distributed by. Figure 2 shows the cracking threshold for 304l and 316l stainless steel as a function of temperature and chloride content. In fresh waters of up to mg l chloride content, type 316 is shown to be resistant to initiation of crevice corrosion in severe crevice geometries. Effects of chloride and oxygen on stress corrosion.

In fresh waters of up to mg l chloride content, type 316 is shown to be resistant to initiation of crevice corrosion in severe. This article describes the susceptibility of 316l stainless steel to stress corrosion cracking scc in a nitritecontaining chloride. Chloride induced stress corrosion cracking of 316 stainless steel oil tube hi everybody, today, i would like to show my case study to you. The higher nickel and molybdenum content in this grade allows it to demonstrate better overall corrosion resistant properties than the 304 alloy, which is especially true in pitting and crevice corrosion within chloride environments. Austenitic steels of type astm 304 and 316 austenitic steels have limited. Types 304 and 316 stainless steel are widely and successfully utilized in piping and equipment to handle fresh waters. The stress corrosion cracking scc and hydrogen embrittlement he behaviors for types 304, 310, and 316 austenitic stainless steels were investigated in boiling saturated magnesium chloride solutions using a constant load method under different conditions including test temperature, applied stress, and sensitization. The stress corrosion cracking scc of aisi 304 and aisi 316 austenitic stainless steels in 0. Chlorine in contact with water and as a dissolved gas, sometimes found in water treatment applications, is potentially aggressive to stainless steels. The following shows some of those temperatures for alloys we typically see associated with scc. Sour service limits of dualcertified 316316l steel twi. Chloride stress corrosion cracking and 316 stainless steel moltenmetal chemical 20 jul 11 07.

Chloride stress corrosion cracking in austentic hse. Lowcarbon versions, such as 316l or 304l, have carbon contents below 0. Austenitic stainless steels chloride induced stress. The molybdenum gives 316 better overall corrosion resistant properties than grade 304, particularly higher resistance to pitting and crevice corrosion in chloride environments. Three general classifications are used to identify stainless steels. What is temperature it is more important than concentration of chloride and anything higher than room temperature higher is worse. Deterioration by clscc can lead to failures that have the potential to release stored energy andor hazardous substances. In this case, the most fashion of failure mode in ss is present.

Stress corrosion cracking of aisi 304 and aisi 316 austenitic. Chloride stress corrosion cracking inspectioneering. Type 316 stainless steel in an environment of 25% phosphoric acid, and. Stress corrosion cracking facts and how to reduce the risk. This alloy exhibits superior resistance to stresscorrosion cracking in boiling 2040% sulfuric acid. It is found that the stress vs timetofailure curves for both alloys are divided into three regions that. It accounts for about 20% of all stainless steel produced. Occasionally, conditions are encountered that cause localized attack, usually crevice corrosion, of these alloys. Yes 300 ss is quite useful and is found in many applications where the risk of cscc would appear to preclude its use. Exposure to room temperature environment showed parabolic weight loss behaviour, with corrosion rates of up to 0. Austenitic stainless steels chloride induced stress corrosion cracking cscc chumpes petroleum 16 mar 18 10. Scc in a 316 stainless steel chemical processing piping system.

Effects of thiosulfate on susceptibility of type 316. Chloride stress corrosion cracking in austenitic stainless. Stress corrosion cracking scc is a common issue with many specialty alloys. Chlorideassisted stresscorrosion cracking in type 316. It is difficult to control the temperature, while changing pipe material or eliminating residual stresses associated with welding and forming the pipework is costly and. Chlorideinduced stress corrosion cracking of 316 stainless.