High-strength steel material having excellent low-temperature strain aging impact properties and method for manufacturing same
a high-strength steel and impact technology, applied in the field of steel materials, can solve the problems of increasing the strength of steel materials, increasing the complexity of mining and storage facilities, and reducing the difference between fracture strength and strength, and achieve excellent low-temperature stain aging impact properties and high strength
Pending Publication Date: 2018-12-20
POHANG IRON & STEEL CO LTD
View PDF0 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Benefits of technology
The patent is about a type of steel that has excellent resistance to low-temperature staining and impacts, while also being strong. This steel can be used for things like pressure vessels and offshore structures, which are getting bigger and more complicated these days.
Problems solved by technology
Recently, mining areas have moved to deep-sea areas or areas of extreme cold due to the exhaustion of energy resources, and thus, mining and storage facilities are becoming larger and more complicated.
Therefore, when subjecting the steel material to cold deformation for manufacturing to form a steel pipe or other complicated structure, the yield strength of the steel material is increased as deformation continues, and thus, the difference from the fracture strength becomes smaller, accompanied by decreased impact toughness.
However, as structures and the like are continuously becoming larger and more complicated, the cold deformation amount required for the steel material is increased, and also the temperature of a use environment is lowered to the level of arctic sea temperature.
Thus, it is difficult to effectively prevent toughness decrease by strain aging of the steel material, with conventional methods.(Non-patent document 1) Effect of Ti addition on strain aging of low-carbon steel wire rod (Ikuo Ochiai, Hiroshi Ohba, Iron and Steel, Volume 75 (1989), issue 4, p.
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 moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
examples
[0076]The steel slabs having the component composition shown in the following Table 1 were subjected to reheating, hot rolling and normalizing heat treatment under the conditions shown in the following Table 2, thereby manufacturing hot-rolled steel plates having a final thickness of 6 mm or more.
[0077]The microstructure fraction, size and carbonitride fraction of each of the manufactured hot-rolled steel plates were measured. In addition, a Charpy impact transition temperature was measured in the state of being aged at 250° C. for 1 hour after 5% stretching of a cold deformation amount, which may represent strength (tensile strength and lower yield strength) and strain aging impact properties of each hot-rolled steel plate, and represented in the following Table 3.
[0078]For the microstructure of each hot-rolled steel plate, the steel plate section was polished with a mirror surface, and etched with Nital or Lepera as desired, thereby measuring an image for a certain area of a speci...
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
| Property | Measurement | Unit |
|---|---|---|
| crystal grain size | aaaaa | aaaaa |
| size | aaaaa | aaaaa |
| temperature | aaaaa | aaaaa |
Login to View More
Abstract
The present invention relates to a steel material for pressure vessels, offshore structures and the like and, more specifically, to a high-strength steel material having excellent low-temperature strain aging impact properties and a method for manufacturing same.
Description
TECHNICAL FIELD[0001]The present disclosure relates to a steel material used as a material for pressure vessels, offshore structures and the like, and more particularly, to a high-strength steel material having excellent low-temperature strain aging impact properties, and a method for manufacturing the same.BACKGROUND ART[0002]Recently, mining areas have moved to deep-sea areas or areas of extreme cold due to the exhaustion of energy resources, and thus, mining and storage facilities are becoming larger and more complicated. Steel materials used therein are required to have excellent low-temperature toughness for securing high strength and facility stability for reducing weight.[0003]Meanwhile, since cold deformation often occurs in the course of manufacturing a steel material having strength and toughness as described above to form a steel pipe or other complicated structures, the steel material is required to significantly avoid a decrease in toughness due to strain aging by cold ...
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
Login to View More Patent Type & Authority Applications(United States)
IPC IPC(8): C22C38/58C22C38/48C22C38/46C22C38/44C22C38/42C22C38/50C22C38/06C22C38/02C22C38/00C21D8/02C21D6/00
CPCC22C38/58C22C38/48C22C38/46C22C38/44C22C38/42C22C38/50C22C38/06C22C38/02C22C38/001C21D8/0263C21D6/004C21D6/008C21D6/005C21D2211/005C21D2211/009C21D2211/002C21D8/02C21D8/0205C21D8/0226C21D9/46C22C38/00C22C38/002C22C38/04
Inventor UM, KYUNG-KEUNKIM, WOO-GYEOMLEE, HONG-JU
Owner POHANG IRON & STEEL CO LTD