Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Structural high-strength thick steel plate excellent in brittle crack propagation stop characteristic and manufacturing method thereof

A technology of brittle crack propagation and stop characteristics, which is 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: 2016-03-23
JFE STEEL CORP
View PDF7 Cites 0 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 reheating, and applying processing during the reheating. It is difficult to control the scale, especially for thick-walled materials with a plate thickness greater than 50mm, which is a process with a large load on rolling and cooling equipment

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
  • Structural high-strength thick steel plate excellent in brittle crack propagation stop characteristic and manufacturing method thereof
  • Structural high-strength thick steel plate excellent in brittle crack propagation stop characteristic and manufacturing method thereof
  • Structural high-strength thick steel plate excellent in brittle crack propagation stop characteristic and manufacturing method thereof

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 (YieldStrength), Tensile Strength (TensileStrength).

[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...

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
thicknessaaaaaaaaaa
thicknessaaaaaaaaaa
thicknessaaaaaaaaaa
Login to View More

Abstract

Provided is a high-strength thick steel plate for structural use having a thickness of 50 mm or more and excellent brittle crack arrestability which can be preferably used for ships and a method for manufacturing the steel plate. The steel plate with excellent brittle crack arrestability has a metallographic structure mainly including a bainite phase, a texture in which the integration degree I of the RD / / (110) plane in a central portion in the thickness direction is 1.5 or more, and a Charpy fracture appearance transition temperature vTrs in a surface portion and the central portion in the thickness direction of -40°C or lower. Further, the steel plate preferably has the Charpy fracture appearance transition temperature and the integration degree I of the RD / / (110) plane in the central portion in the thickness direction satisfying the relational expression (1) below: vTrs 1 / 2 �¢ t - 12 × I RD / / 110 �¢ 1 / 2 �¢ t ‰¤ - 70 where vTrs (1 / 2t) : fracture appearance transition temperature (°C) in the central portion in the thickness direction and I RD / / (110) [1 / 2t] : integration degree of the RD / / (110) plane in the central portion in the thickness direction.

Description

technical field [0001] The present invention relates to a high-strength thick steel plate for structural use (high-strength thick steel plate) excellent in brittle crack arrestability (brittle crack arrestability) and a manufacturing method thereof, and particularly relates to a high-strength thick steel plate suitable for ships with a plate thickness of 50 mm or more . 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 toughness at the operating temperature (toughness), brittle crack propagation stop characteristics are required. [0003] Vessels such as container ships and bulk carriers use high-strength thick-walled materials for their outer plate (outer plate of ship'shull) in their structures, but recently, along with the increase in size of ship hulls, high-strength thick-walled materials have fur...

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 Patents(China)
IPC IPC(8): C22C38/14C22C38/58C21D8/02
CPCC21D8/02C21D8/0205C21D8/0226C21D8/0263C21D2201/05C21D2211/002C22C38/00C22C38/001C22C38/02C22C38/04C22C38/06C22C38/08C22C38/12C22C38/14C22C38/16C22C38/18
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 Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com