High-strength thick steel plate for construction having excellent characteristics for preventing diffusion of brittle cracks, and production method therefor

A technology for brittle crack propagation and stop characteristics, applied in the field of high-strength thick steel plates, can solve the problems of difficult control of production scale and large load, and achieve the effect of excellent brittle crack propagation stop characteristics and improved safety.

Active Publication Date: 2014-09-03
JFE STEEL CORP
View PDF7 Cites 7 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0011] However, the steel materials with excellent brittle crack propagation stopping properties described in Patent Documents 1 and 2 obtain a specific structure by cooling only the surface layer of the steel material and then reheatin

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
  • High-strength thick steel plate for construction having excellent characteristics for preventing diffusion of brittle cracks, and production method therefor
  • High-strength thick steel plate for construction having excellent characteristics for preventing diffusion of brittle cracks, and production method therefor
  • High-strength thick steel plate for construction having excellent characteristics for preventing diffusion of brittle cracks, and production method therefor

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0115] Melt molten steel (steel symbols A to O) with the compositions shown in Table 1 in a converter, form steel raw materials (slab thickness: 250 mm) by continuous casting, hot-roll to a plate thickness of 50 to 90 mm, and then cool , to obtain No.1-30 steel for testing. Table 2 shows hot rolling conditions and cooling conditions.

[0116] For the obtained thick steel plate, a Φ14mm JIS14A test piece was cut from 1 / 4 of the plate thickness so that the longitudinal direction of the test piece was at right angles to the rolling direction, and a tensile test was performed to measure the yield point (Yield Strength) , Tensile Strength.

[0117]In addition, a JIS No. 4 impact test piece was cut from 1 / 2 of the plate thickness so that the long axis direction of the test piece was parallel to the rolling direction, and a Charpy impact test was performed to obtain the fracture transition temperature. Here, the impact test piece of the surface layer is a test piece in which the su...

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

No PUM Login to view more

Abstract

Provided are: a high-strength thick steel plate for construction having excellent characteristics for preventing the diffusion of brittle cracks, said plate being used for ships and having a preferred plate thickness of at least 50 mm; and a method for producing the thick steel plate. The thick steel plate has excellent characteristics for preventing the diffusion of brittle cracks, characterized in that: the main constituent of the metal structure is bainite; the steel plate has an aggregate structure in which the density (I) in the RD//(110) plane at the plate thickness center is at least 1.5; and the Charpy fracture appearance transition temperature (vTrs) at the surface and plate thickness center is not more than -40 DEG C. More preferably, the Charpy fracture appearance transition temperature (vTrs) at the plate thickness center, and the density (I) in the RD//(110) plane satisfy formula (1). vTrs(1/2t) - 12 IRD//(110)[1/2t] <= -70 ...(1), wherein, vTrs(1/2t) is the fracture appearance transition temperature at the plate thickness center ( DEG C), and IRD//(110)[1/2t] is the density in the RD//(110) plane at the plate thickness center.

Description

technical field [0001] The present invention relates to a high-strength thick steel plate (for structural use) excellent in brittle crack arrestability (brittle crack arrestability) and a manufacturing method thereof, and particularly relates to a plate suitable for use in ships with a thickness of High-strength thick steel plate above 50mm. Background technique [0002] For large structures such as ships, because brittle fracture accidents have a great impact on the economy and the environment, it is generally required to improve safety. For the steel used, the impact on the operating temperature Toughness and brittle crack propagation stop properties are required. [0003] Vessels such as container ships and bulk carriers use high-strength thick-walled materials as the outer plate of the ship's hull in their structures, but recently, along with the increase in the size of the hull, high-strength thick-walled materials have further progressed. Generally, the higher the st...

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
IPC IPC(8): C22C38/14C22C38/58C21D8/02
CPCC22C38/14C22C38/04C22C38/58C21D8/0205C22C38/001C22C38/18C22C38/02C21D8/02C22C38/12C22C38/06C22C38/08C22C38/16C21D2211/002C21D8/0226C21D8/0263C21D2201/05C22C38/00
Inventor 竹内佳子长谷和邦三田尾真司村上善明
Owner JFE STEEL CORP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap