Martensitic stainless steel and manufacturing method thereof

Abstract

The invention relates to martensitic stainless steel. The martensitic stainless steel comprises the following chemical components in percent by weight: 0.13-0.23% of C, less than 1.0% of Si, less than 1.0% of Mn, less than or equal to 0.030% of P, less than or equal to 0.010% of S, 12.0-14.0% of Cr, 0.070-0.120% of N, less than 1.0% of Ni, 0.9-1.5% of Mo, and the balance of Fe and inevitable impurities, wherein the content of C and N meets the formula as follows: the sum of C and N is larger than or equal to 0.20% and is less than or equal to 0.33%. The steel is manufactured by the following steps of: heating a steel billet or a continuous casting billet at the temperature ranging from 1100 DEG C to 1250 DEG C, carrying out rolling, and finishing final rolling at the temperature more than 900 DEG C; then carrying out annealing treatment with the annealing temperature of 800-900 DEG C and the annealing time of 4-8 hours; and then carrying out normalizing treatment with the normalizing temperature of 1000-1200 DEG C and the normalizing time of 2-5 hours. The martensitic stainless steel has good machining performance and excellent corrosion resistance after heat treatment, and is suitable for being used for manufacturing molds, surgical and medical instruments, knives and scissors and the like.

Description

technical field [0001] The invention relates to a martensitic stainless steel used for manufacturing moulds, surgical and medical instruments, knives, scissors, etc. and a manufacturing method thereof, which has good machining performance and excellent corrosion resistance after heat treatment. Background technique [0002] Compared with other types of stainless steel, martensitic stainless steel has the advantages of high hardness, strong wear resistance and low cost, so it is widely used in molds, knives and scissors, surgery and medical equipment and other industries. These industries require steel to have sufficient hardness and wear resistance, and the requirements for corrosion resistance are getting higher and higher, and the cost problem is also becoming more and more prominent. From the perspective of composition design, traditional martensitic stainless steel (such as 2Cr13, 3Cr13, 4Cr13 series) mainly controls the hardness of the steel after heat treatment by cont...

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Problems solved by technology

Among them, JP2009-203528A guarantees corrosion resistance through high chromium equivalent (15-16.6%), but due to the high carbon content, the corrosion resistance is still at a level close to 2Cr13; FR2920784A has high C and N content, while Cr content is relatively high Low (10-12.4%), the loss of corrosion resistance is guaranteed to be compensated by adding Mo, but the corrosion resistance can only reach a level close to 2Cr13; the alloy composition system co

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