Cold and Hot Workability of 00Cr25Ni7Mo3WCuN Steel

925Cr25Ni7Mo3WCuN Steel Cold and Hot Deformation Processing Performance

Cr25Ni7Mo3WCuN steel is a high-alloy hardfacing material developed by the petrochemical industry. It has a high wear resistance and is widely used in various wears and corrosive welding materials for various types of pipelines and valves operating at different temperatures. Due to its good wear resistance and corrosion resistance, it has good cold and hot deformation processing performance. Its maximum hardness is up to 50-56HRC, the average hardness is 48-52HRC, and its hardness uniformity coefficient is less than 0.4.

The cold processing performance of Cr25Ni7Mo3WCuN steel is good, it has high cold work hardening ability, and its yield strength generally increases with the increase of deformation degree. Its tensile strength can be more than 1100MPa. However, its cold cracking resistance is not high and its mechanic performance is relatively poor, which makes the deformation part prone to the phenomenon of uneven deformation, broken teeth and so on. Therefore, the amount of deformation in the cold processing of Cr25Ni7Mo3WCuN steel should be founded carefully and step-by-step processing should be held. It is better to select tools with good sharpness and moderate hardness, and to reduce the amount of deformation at each time, preferably not more than 20% of total deformation.

The hot deformation performance of Cr25Ni7Mo3WCuN steel is not ideal due to its less thermal strength and large diffusion coefficient, which means that its heat treatment performance is general. It can not be annealed , tempered or quenched directly, even with small amount of deformation at high temperatures. Therefore, in hot deformation processing of Cr25Ni7Mo3WCuN steel, a transition process should be bought in, i.e. performing pre-heating treatment and cooling step by step. Temperature of pre-heating and cooling should be controlled strictly. If temperature is too low A and Cr will diffuse at the grain boundaries of steel causing brittleness to be increased. If temperature is too high, Cr and Mo in steel will diffuse into the liquid at grain boundaries and formed non-metallic compounds, resulting in a decrease in mechanical properties. The best preheating temperature should be above 1000℃ and quenching temperature should be below 750℃ when hot deformation processing of Cr25Ni7Mo3WCuN steel.

In summary, Cr25Ni7Mo3WCuN steel has good wear resistance and corrosion resistance. Its cold and hot deformations processing performance is general, but it can be improved by pre-heating and cooling step by step. In order to obtain good process effect,it is necessary to operate strictly in accordance with the process conditions, master the hot and cold processing technology characteristics of Cr25Ni7Mo3WCuN steel, and control parameters such as deformation amount, pre-heating temperature and cooling temperature, in order to achieve the purpose of improving the properties of Cr25Ni7Mo3WCuN steel.

Duplex stainless steel S32750 (00Cr25Ni7Mo3WCuN) is a duplex stainless steel designed for moderate to high stress corrosive environments. It has excellent weldability, good ductility, and high strain hardenability, making it well suited for fabrication of machinery or components with moderate to high stress-corrosion environments.

The duplex stainless steel S32750 is a ferritic-austenitic stainless steel which contains 25% chromium, 7% nickel and 3% molybdenum, combined with a high tungsten content. It offers excellent corrosion resistance, especially in chloride-containing environments, making it a suitable choice for a wide range of applications from marine environments to industrial equipment.

S32750 has very good weldability and it can be cold rolled and annealed without showing any signs of heat affected zones. It displays good ductility and very high strain hardenability allowing for excellent formability, toughness and strength. These characteristics make it a suitable choice for fabrications with moderate to high stress-corrosion environments.

The cold machinability of S32750 is similar to that of austenitic stainless steels due to its high ferritic content. It can be machined at a relatively slow speed with a light cutting force, but ultimate cutting speed and feed rate will be slightly lower than for austenitic stainless steel, depending on the cutting edge conditions.

The hot workability of S32750 is excellent due to its high ferritic content. It can be hot worked in the temperature range of 980°C-1000°C. Hot working at higher temperatures can be used to finish difficult to shape components. It can also be hot forged, but the temperature must be decreased from 1100°C to 980°C due to the reason that different temperature may cause the formation of brittle phase.

In conclusion, S32750 has good ductility and strain hardenability, making it well suited for fabrication of machinery or components with moderate to high stress-corrosion environments. It is resistant to corrosion and has light cold machinability and excellent hot workability. All these characteristics make S32750 an ideal metal for many applications.