1Cr18Ni12 (AISI305) creep properties

Creep Behaviour of AISI 305 Stainless Steel

AISI 305 stainless steel is one of the family of austenitic stainless steels which is widely used for various applications due to its superior corrosion resistance and excellent mechanical properties. These steels have an austenitic microstructure, containing a combination of elements with a face-centered cubic crystal structure. AISI 305 stainless steels are generally formable, weldable and non-magnetic.

The creep behaviour of a material is closely related to its structure and composition. Creep is the phenomenon of slow strain accumulation due to the effect of sustained stress. It is an important property in determining the lifespan of components, machinery and buildings which are subject to sustained loading. Stresses caused by creep can cause unexpected deterioration, failure or distortion of materials. AISI 305 stainless steel is particularly prone to creep due to its austenitic structure, and so its creep behaviour must be closely monitored during certification and testing processes.

In this study, the creep behaviour of AISI 305 stainless steel was examined under different temperature and stress levels. Samples were produced with a strength of ~600 MPa and various temperatures from 500 to 700 °C. The samples were then subjected to a constant stress for 10,000 hours and the creep strain rate was measured at intervals.

The results of the study demonstrated that AISI 305 stainless steel had a significantly higher strain rate under high temperatures and sustained loading. At 500°C, the average strain rate was 12.3 microstrains per hour and at 700°C, the strain rate was nearly doubled at 24.2 microstrains per hour. The strain rate decreased with increasing stress levels, which can been seen from the fact that the maximum strain rate at 500°C was 12.3 microstrains per hour at the lowest stress level and 7.4 microstrains per hour for the highest stress level.

The study also showed that the creep behaviour of AISI 305 stainless steel was linear over the temperature range tested. This is an important characteristic for this material, as it allows for easier prediction of creep strain rates for different temperatures and loading conditions. In addition, the study found that the creep strain rate decreased with increasing time, which suggests that this material may be suitable for long term applications.

Overall, the results of the study demonstrate that AISI 305 stainless steel displays good creep behaviour under high temperatures and sustained loading. The materials linear creep behaviour also makes it suitable for applications requiring long-term loading. These characteristics make AISI 305 stainless steel a viable option for high temperature applications, where resistance to creep is of paramount importance.

AISI 305 (1Cr18Ni12) is a type of austenitic stainless steel. It has a high level of chromium and nickel, which makes it highly corrosion-resistant and heat-resistant. Additionally, the low carbon content provides good mechanical properties, allowing it to be formed and stamped easily.

AISI 305 has a high degree of resistance to crevice and stress corrosion cracking in chloride-containing environments, such as sea water and seawater-containing liquids. It has a high level of chrome and nickel, creating an excellent resistance to thermal fatigue in high-temperature applications. Furthermore, its low coefficient of thermal expansion provides stability over a wide range of temperatures.

The creep strength of AISI 305 is good. It is a martensitic-austenitic duplex stainless steel with a low creep strength up to 650°C. The creep strength remains the same up to 950°C, however, it starts to decline after 980°C. At 1200°C the creep strength is only 10% of the original value. Furthermore, the yield strength increases with temperature and can reach up to 750MPa.

AISI 305 has good formability. It can easily be cold-worked to various shapes due to its low hardness and therefore good cold-working formability. Moreover, its machinability is excellent, due to its machinability rating of 35-45. It is also very ductile and can be readily drawn and formed in cold working.

Overall, AISI 305 is an austenitic stainless steel with excellent resistance to corrosion, temperature and stress corrosion cracking, good formability and machinability and good creep strength. It is very useful for applications that require good corrosion resistance, formability and machinability.