Unlock instant, AI-driven research and patent intelligence for your innovation.

Martensite stainless steel

A martensitic stainless steel, high-quality technology, applied in the field of martensitic stainless steel, can solve the problems of Cr content, high strength and reduced toughness

Inactive Publication Date: 2007-01-10
SUMITOMO METAL IND LTD
View PDF0 Cites 11 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Such high C, Cr content and high strength reduce the toughness of the product

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Martensite stainless steel
  • Martensite stainless steel

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0027] Seamless steel pipes containing the components of the examples described in Table 1 were produced. First, heat the billet to above 1200°C and punch it with a piercer. The steel pipe thus obtained was heated to a predetermined temperature in a reheating furnace, followed by final finish rolling with a mandrel mill / reducing mill to obtain predetermined dimensions (outer diameter: 177.8 mm, wall thickness: 10.36 mm). Thereafter, the steel pipe was air-cooled to normal temperature at 2°C / sec, followed by heat treatment. The heat treatment conditions were as follows. Quenching: 960°C x 10 minutes, air cooling at a cooling rate of 5°C / sec or less. After quenching, adjust the tempering temperature so that the strength meets APIL80 grade (yield point stress is 552-656MPa) and temper.

[0028] Cut out API 5CT test pieces from the steel pipes manufactured by the above method, measure the tensile strength, yield strength, and average hardness of the arc-shaped test pieces, and ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
yield strengthaaaaaaaaaa
Login to View More

Abstract

The invention relates to a seamless steel tube using martensitic stainless steel that has good tenacity and could be used in oil well pipe. It contains 0.15-0.21wt% C, 0.05-1.00wt% Si, 0.3-1.00% Mn, 10.5-14.00wt% Cr, below 0.01wt% Al, below 0.05wt% P, below 0.01wt% S, 0-0.05wt% Ti, 0-0.50wt% V, 0-0.02wt% Nb, below 0.1wt% N, and the rest is iron and impurity. The Cr-carbon-nitrogen compound separating out from grain boundary is below 5%.

Description

technical field [0001] The present invention relates to martensitic stainless steel having excellent toughness, especially martensitic stainless steel for seamless steel pipes used for oil well pipes and the like. Background technique [0002] Martensitic stainless steel such as API-13Cr, which is mainly used as oil well pipe, requires a yield strength above 80ksi (552MPa). In order to meet this strength requirement, the content of C is generally set at about 0.2% during component design. Here, "%" related to the component content (excluding the amount of Cr carbonitride precipitated at the grain boundary) all represent "mass %". Such high C, Cr content and high strength lower the toughness of the product. Therefore, increasing the toughness of 13Cr martensitic stainless steel has become an important technical issue, and various methods for improving toughness have been proposed so far. Contents of the invention [0003] It is an object of the present invention to provi...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): C22C38/50C21D1/18C21D6/00C21D9/08E21B17/00
CPCC22C38/02C22C38/04C22C38/24
Inventor 森伸行中村圭一
Owner SUMITOMO METAL IND LTD