Stainless Steel Casting Good Impact Performance
With chromium as the main alloying element, Stainless Steel Casting the amount of Cr is generally between 13% and 30%. Has a good resistance to oxidation of the medium corrosion resistance and resistance to air oxidation at high temperatures, can also be used as heat-resistant steel. Stainless Steel Casting The welding performance of this kind of steel is poor. When the chromium content is more than 16%, the as-cast structure is coarse, and long-term insulation between 400-525 ℃ and 550-700 ℃, there will be "475 ℃" brittle phase and σ phase, the steel brittle. The brittleness at 475 ° C is related to the ordering of Cr-containing ferrite. 475 ℃ brittle phase and σ phase brittle, Stainless Steel Casting can be heated to 475 ℃ above and then fast to improve. The brittleness at room temperature and the brittleness of the post-weld heat affected zone are also one of the basic problems of ferritic stainless steel. Vacuum refining can be used to add trace elements such as boron, rare earth and calcium, or austenite forming elements such as Ni, Mu, N, Cu, etc.) approach to be improved. In order to improve the mechanical properties of the weld zone and the heat affected zone, a small amount of Ti and Nb are usually added to prevent grain growth in the heat affected zone. Commonly used ferrite steel has ZGCr17 and ZGCr28. The impact toughness of this type of steel is low, Stainless Steel Casting in many cases by high nickel austenitic stainless steel replaced. Ni content of more than 2%, containing more than 0.15% N of ferritic steel has a good impact performance.
In the stainless steel casting process, there are often stomatal problems, to the casting process to bring a lot of trouble, the stomata is the metal liquid during the cooling and solidification process, Stainless Steel Casting the precipitation of gas in the ingot formed in the bubble defects.
Stainless steel casting surface cleaning is divided into dry and wet two categories, Stainless Steel Casting dry cleaning method is mainly shot blasting, wet cleaning method is mainly a little solution of hydraulic sand, water clear sand, etc.
Dry clean-up method is to blasting the main treatment of the surface of the stainless steel casting surface cleaning, shot blasting treatment is simply to use compressed air as the driving force, Stainless Steel Casting so that the projectile to a certain speed jet to the surface of stainless steel castings, remove the surface Of the sand and iron oxide skin, but this friction cleaning method due to low efficiency, Stainless Steel Casting clean up uneven, poor results and other reasons, has been used by the factory, has been almost eliminated.
Stainless steel according to the structure can be divided into body stainless steel, martensitic stainless steel, ferritic stainless steel. Austenitic stainless steel is the largest use of a stainless steel, Stainless Steel Casting body structure of stainless steel is theoretically no magnetic, but after cold processing of stainless steel will produce magnetic, according to some domestic and foreign research shows that lead to stainless steel cast with magnetic The reason is that the stainless steel will change when the stainless steel is heated above the transition temperature for a period of time, but then the stainless steel castings need to be cooled and formed. Stainless Steel Casting During the rapid cooling process, when the temperature is reduced to the martensitic transition temperature, The organization begins to change to martensite, until the temperature falls below the formation of the martensitic transition temperature.