Stress corrosion of alloy tube

When crises break between austenite no metal precipitation, molybdenum has little effect on the mechanical properties at room temperature. However, alloy pipe factory, with the molybdenum content increases alloy tube plant, high temperature strength of the steel to improve the embarrassing situation, such as long-lasting, creep properties were greatly improved, so the stainless steel containing molybdenum is also often used quality efficiency at high temperatures, However, the addition of molybdenum steel high temperature deformation resistance increases, coupled with the presence of small amounts of steel often δ ferritic stainless steel containing molybdenum therefore keen workability is worse than molybdenum-free steel, and molybdenum content is higher Powei, thermal processing the worse the performance.

Also alloy tube plant, molybdenum-containing austenitic stainless steel easy one million κ (σ) phase precipitation, which will significantly deteriorate the plasticity and toughness of the steel, so the molybdenum-containing austenitic stainless steel production increased dividend, equipment manufacturing and application process, we should pay attention to prevent inter-formed steel in the metal phase.

Tianjin Seamless Steel Tube Plant was informed that the main role of molybdenum in the austenitic stainless steel is to improve the corrosion resistance and resistance to reducing media point of corrosion, crevice corrosion resistance properties and the like. Respectively molybdenum chromium nickel austenitic stainless steel corrosion resistance of the medium, nitric acid, sulfuric acid around the corner, acetic alloy tube plant, phosphoric acid and urea in, it can be seen, in addition to HNO3 in place, the role of molybdenum in both oxidizing media is useful, therefore molybdenum-containing austenitic stainless steel is generally not resistant to nitric acid corrosion-day economic downturn, unless market confidence nitrate containing F-, Cl- plasma.

Resistant high concentration of chloride stress corrosion sinking, although a finger with this experiment. Resistance to stress corrosion harmful false records of molybdenum austenitic stainless steel but due to common chrome-nickel austenitic stainless steel containing more than trace amounts of chloride and oxygen saturation using an aqueous medium, the stress corrosion pitting again for the origin, Therefore, austenitic chromium-nickel-molybdenum stainless steel containing molybdenum due to the high resistance to pitting corrosion increasingly meager, so in practical applications often than not contain molybdenum steel has better resistance to chloride stress corrosion.

Although the role of alloying elements molybdenum austenitic stainless steel resistant to reducing media due to surface pitting and crevice corrosion is not entirely clear, but a large number of experiments have indicated alloy tube plant, corrosion effect of Mo steel contains only quite high when the amount of chromium effectively cooperate closely, molybdenum is mainly to strengthen the role of corrosion resistant chromium steel, at the same time, corrosion inhibition molybdenum salt after formation has also been confirmed by experiment.