Place in the strip rolling direction, wrinkling is ferritic stainless steel in the molding process should Variable A surface defect is easy to produce larger Indicates a narrow stripe projection, namely the surface wrinkles. It can reduce the wrinkling by controlling the production process: increase equiaxed. Methods include:
① crystal axis electromagnetic stirring can promote transition to columnar grains and the like.
② in the metal solidification process or prior to solidification of molten metal is applied to the pulse current, a reduction of the columnar crystal slab. Pulse current and the solidifying metal subjected to strong electromagnetic force and the impact force generated by the vibration, the self-induction the interaction of the magnetic field generated by the pulse was first crystallized dendrites are broken and the formation of more crystalline core, so that the solidification structure was refined through the cooling zone the better. Appropriate amount of water,
③ control forefront of solid-liquid interface components to reduce the solid phase during solidification temperature of the liquid steel gradient; after the end of solidification, grains still grow from time to time, especially above 900 ℃, grain growth quickly.
Therefore, the cooling rate should be appropriate to accelerate the solidification late. Slowed grain growth. Low finishing temperature and high annealing temperatures. Almost all the shortcomings ferritic stainless steel performance on both the carbon and nitrogen related. With the increase of carbon and nitrogen content of 2 to select a suitable slab heating temperature of ferritic stainless steel brittle transition temperature impact toughness was on the move, fall, especially when the steel chromium content higher than 15% 18% more obvious ; notch sensitivity, the cooling rate effect and size effect of steel but also with steel carbon, nitrogen increases significantly enhanced; + N amount increases with C, resistance to general corrosion of carbon, nitrogen ferritic stainless steels, ferritic between susceptibility to intergranular corrosion of stainless steel to increase resistance to pitting, crevice corrosion and stress corrosion are also harmful oxygen content in steel has a similar impact, increases with the oxygen content.
Post time: Oct-28-2019