High-yield-ratio, high-strong toughness cast martensite stainless steel and production method thereof

Abstract

The invention is martensitic stain less steel with high yield ratio and high ductility, the character is that it contains: C is not more than 0.06%, Cr 11-16.5%, Ni 3.50-6.0%, Mn is not more than 2%, Mo 0.5-2%, Si is less than 1%, the residue are Fe and a little impurity. The impurity includes Al, [O], [N], [H], S, P, the content of then are Al <0.15%, [O]<0.01%, [N]<0.03%, [H] is not more than 0.0005%, S is not more than 0.020%, P is not more than 0.025%. The invention can enhances the synthesis performance index (high density, high rigidity, high ductility and yield ratio, excellent welding processing property, and fatigue preventing property under water) greatly, it can ensure that the stress of large wheel is smaller than 1/3 of material yield ratio, the stress of large welding wheel is smaller than 1/2 of material yield density. It maintains the higher etching preventing property and sand grinding resisting property.

Description

(1) Technical field [0001] The invention relates to a metal material, in particular to a casting martensitic stainless steel material and a production method thereof. (2) Background technology [0002] Since the 1970s, in the field of hydropower engineering in the world, cast low-carbon martensitic stainless steel (0Cr13Ni4 type) has been successfully applied to hydroelectric unit runners, blades and guide vanes and other flow-passing parts, showing good room temperature and low temperature. Mechanical properties, underwater fatigue properties, welding process properties and anti-cavitation wear service performance. In the field of foundry technology, it is known as "the successful steel type that the foundry dreamed of". my country, represented by Shenyang Foundry Research Institute, has been engaged in the development and engineering application of 0Cr13Ni4Mo and 0Cr16Ni5Mo casting low-carbon martensitic stainless steel materials since 1972. In 1981, my country's self-de...

AI Technical Summary

Problems solved by technology

It cannot meet the design requirement that the residual stress of the runner is less than 50% of the yield strength of the material

The high-efficiency runner adopts higher design stress, such as the maximum design stress of the runner of Xiaolangdi Power Station, which is 270MPa, but the current applied materials cannot guarantee the reliability requirement that the maximum design stress should be less than 1 / 3 of the yield strength

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