Hot-rolled steel sheet and method for manufacturing same

A technology for hot-rolled steel sheets and manufacturing methods, applied in metal rolling, manufacturing tools, heat treatment furnaces, etc., can solve problems such as environmental load concerns, and achieve excellent corrosion resistance, chemical conversion treatment, and coating film adhesion. Effect

Active Publication Date: 2021-05-14
NIPPON STEEL CORP
View PDF16 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, there is concern about the environmental load caused by phosphorus and metals in the waste liquid that is discarded after use.
In addition, a large amount of sludge mainly composed of iron phosphate deposited in the chemical conversion treatment tank has a large environmental load as industrial waste.

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
  • Hot-rolled steel sheet and method for manufacturing same
  • Hot-rolled steel sheet and method for manufacturing same
  • Hot-rolled steel sheet and method for manufacturing same

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0226] Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited to these Examples.

[0227] Steels having the chemical compositions shown in Steel Nos. A to V in Table 1A and Table 1B (Table 1B is a continuation of Table 1A) were melted and continuously cast to manufacture slabs with a thickness of 240 to 300 mm. The obtained slab was heated to the temperature shown in Table 2A and Table 2B using a regenerative burner. At this time, the air in the preheating zone (preheating zone), heating zone (heating zone), and soaking zone (soaking zone) was controlled as shown in Table 2A and Table 2B.

[0228] The heated slabs were hot-rolled at the finish rolling temperatures shown in Table 2A and Table 2B. After hot rolling, cooling was performed under the cooling conditions shown in Table 2A and Table 2B, and coiling was performed after cooling.

[0229] The obtained hot-rolled steel sheets of Production Nos. 1 to 35 were observed f...

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
tensile strengthaaaaaaaaaa
strengthaaaaaaaaaa
surface roughnessaaaaaaaaaa
Login to view more

Abstract

A hot-rolled steel sheet has a specified chemical composition, wherein, when the thickness of the steel sheet is defined as "t", a metallographic structure lying between a surface of the steel sheet and a depth t / 4 from the surface in the steel sheet contains tempered martensite and / or lower bainite in a total volume fraction of 90% or more, the tensile strength is 980 MPa or more, and the average Ni concentration in the surface is 7.0% or more.

Description

technical field [0001] The present invention relates to a hot-rolled steel plate and a manufacturing method thereof. [0002] This application claims priority based on Japanese Patent Application No. 2018-197935 for which it applied in Japan on October 19, 2018, and uses the content here. Background technique [0003] In recent years, in order to suppress carbon dioxide (CO2) from automobiles 2 ) emissions, has been using high-strength steel plates to reduce the weight of automobile bodies. In addition, in order to ensure the safety of passengers, a large amount of high-strength steel sheets are used in addition to mild steel sheets in automobile bodies. [0004] Furthermore, recently, due to fuel consumption restrictions, NO X Further stringent environmental regulations are expected to increase the number of plug-in hybrid vehicles and electric vehicles. In these next-generation vehicles, large-capacity batteries need to be installed, and further weight reduction of the...

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): C21D9/46C22C38/00C22C38/58
CPCC22C38/58C21D9/46C22C38/02C22C38/04C22C38/08C22C38/12C22C38/14C22C38/16C22C38/18C22C38/002C22C38/005C22C38/105C22C38/008C21D8/0226C21D8/0263B21C47/02C21D1/02C21D1/19C21D2211/008C21D2211/002C21D2211/004C21D6/005C21D6/02C21D8/021C21D8/0278C21D9/0081C21D1/52C21D1/76C22C38/48C22C38/50C22C38/42C22C38/001C22C38/44C22C38/46C22C38/54C22C38/60B21B1/02B21B2001/028C21D6/004C21D6/007C21D6/008C21D8/0205C22C38/06C23G1/08
Inventor 横井龙雄林田辉树榊原睦海安藤洵甲斐真辅首藤洋志
Owner NIPPON 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