Corrosion of industrial cold-drawn steel pipes is mainly manifested in: a serious form of corrosion of cold-drawn steel pipes is local corrosion (i.e. stress corrosion cracking, pitting corrosion, intergranular corrosion, corrosion fatigue and crevice corrosion). Next, cold-drawn seamless steel pipe manufacturers to focus on the introduction. Cold-drawn seamless steel pipe is a term used to describe the corrosion phenomena occurring on the whole alloy surface in a relatively uniform manner. When the overall corrosion occurs, the village materials gradually become thinner due to corrosion, and even the materials become corroded and invalid.
Stress corrosion cracking (SCC) is a general term used to describe the alternating failure of stress-bearing alloys in corrosive environments due to the expansion of streaks. Stress corrosion cracking has brittle fracture morphology, but it may also occur in materials with high toughness. The necessary condition for stress corrosion cracking is the existence of tensile stress (whether residual stress or applied stress, or both) and specific corrosion medium. The formation and extension of the pattern are approximately perpendicular to the direction of tensile stress. This stress value, which leads to stress corrosion cracking, is much smaller than that required for material fracture without corrosive medium in stainless steel industrial welded pipe. Microscopically, cracks passing through grains are called transgranular cracks, while cracks extending along grain boundaries are called intergranular cracks. When stress corrosion cracks extend to a depth (where the stress on the load-bearing material section reaches its fracture stress in the air), the material breaks off according to normal cracks (in ductile materials, usually through the aggregation of micro-defects). Therefore, the section of the part which has failed due to stress corrosion cracking will contain the characteristic area of stress corrosion cracking and the "dimple" area associated with the aggregation of micro-defects.
Point corrosion: A localized form of corrosion that results in corrosion.
Intergranular corrosion: Intergranular boundaries are the boundaries of disordered and mismatched grains with different crystallographic orientations. Therefore, they are favorable areas for the segregation of various solute elements or precipitation of metal compounds (such as carbides and delta phases) in steel. Therefore, it is not surprising that grain boundaries may be corroded first in some corrosive media. This type of corrosion is called intergranular corrosion. Most metals and alloys may exhibit intergranular corrosion in a specific corrosion medium.
Crevice corrosion: A form of localized corrosion that may occur entirely in a solution-stagnated crevice or in a shielded surface. Such gaps can be formed at metal-to-metal or metal-to-metal joints, such as where rivets, bolts, gaskets, seats, loose surface sediments, and candles are joined to marine life. 标签:
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