High-strength stainless steel cold-rolled sheet strip and manufacturing method thereof

Abstract

A high-strength stainless steel cold-rolled sheet strip and a manufacturing method thereof. The stainless steel cold-rolled sheet strip comprises chemical components of, by weight, no more than 0.02% of C, 0.3-1.5% of Si, 0.5-1.75% of Mn, 0.5-2.0% of Mo, 13.0-16.0% of Cr, 1.0-3.0% of Ni, no more than 0.015% of N, 6(C+N)-0.5% of Nb + Ti, no more than 0.03% of C + N, and the balance of Fe and unavoidable impurities. The obtained stainless steel cold-rolled sheet strip has the following advantages: yield strength no less than 400MPa and tensile strength no less than 600MPa; good plasticity with elongation no less than 16%; and excellent corrosion resistance with point corrosion potential no less than 150mV and corrosion rate no more than 9g / m<2>.h according to GB / T 17899-1999 and GB / T 17897-1999.

Description

technical field [0001] The invention relates to a stainless steel plate and a manufacturing method thereof, in particular to a high-strength stainless steel cold-rolled strip and a manufacturing method thereof. Background technique [0002] When stainless steel is applied to parts involving structural parts, such as structural parts and panels for rail vehicle reinforcement, not only excellent corrosion resistance is required, but also high strength and certain machinability are required. At present, the field generally adopts austenitic 304 and 301L stainless steels that have undergone cold work hardening. The above-mentioned stainless steels contain 6-8% Ni, and the price is relatively high, and the strength increased by cold work hardening will be reduced after heating (such as welding process). These two deficiencies limit its application. [0003] Traditional ferritic-austenitic duplex stainless steel generally contains higher alloy content and higher cost. [0004] A...

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Problems solved by technology

[0007] 1. Chinese patent CN85106667 discloses a ferrite-martensitic dual-phase steel (50% each) with excellent corrosion resistance, which has high strength and good plasticity, and the alloy content is relatively low, but The high-cost Ni and Mo content in the composition system of this patent is relatively high, and the addition of Al and Re brings great difficulty to steelmaking. In addition, from the perspective of manufacturing technology, the product mainly involves heat-removed industrial plates

[0008] 2. The composition system of Chinese patent CN95116438.4 is austenitic-ferritic duplex stainless steel with high alloy content. This alloy has good strength and toughness, especially excellent corrosion resistance, and can be applied in the seawater field. At present, the Type steel has been developed in an all-round way, but due to its high alloy content, it is difficult to produce and the cost is high, so it is not an economical type of steel

[0011] 5. Chinese patent CN1550565A obtains a certain proportion of quenched martensite (more than 20%) by adopting a rapid cooling method, and improves the strength of stainless steel through the martensite structure, and the strength can reach 700MPa, but because the quenched martensite is The hard and brittle phase makes the plasticity of the alloy not good, only about 10%

[0012] 6. Chinese patent CN101748339A provides an ultra-pure ferritic stainless steel containing Nb and Ti. The lower C + N content and the double stability of Nb and Ti ensure the corrosion resistance of the alloy, and the lower alloy content ensures its Economical, but the method of improving the strength of the patent is to introduce a secondary cold rolling with a large deformation rate (>45%) after the cold plate is continuously annealed to improve its strength. The principle is similar to cold deformation hardening, so its plasticity is too poor. Only less than 5%

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