Case hardened steel and method for producing same

A manufacturing method, a technology of hardening steel, applied in the direction of manufacturing tools, furnace types, furnaces, etc., can solve problems such as insufficient cold forgeability, and achieve the effects of shortened order cycle, good cold forgeability, and cost reduction

Inactive Publication Date: 2013-05-29
KOBE STEEL LTD
View PDF10 Cites 16 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The gist disclosed in Patent Documents 1 to 8 is that the number of precipitates (carbides, carbonitrides, etc.) containing Nb and / or Ti having a predetermined particle size and composition are controlled within a predetermined range, thereby enabling To prevent the coarsening of crystal grains, although the effect of preventing grain coarsening can be obtained to a certain extent, the cold forgeability is not sufficient

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
  • Case hardened steel and method for producing same
  • Case hardened steel and method for producing same
  • Case hardened steel and method for producing same

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0061] Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited to the following examples, and can of course be appropriately modified and implemented within the scope of meeting the above-mentioned and hereinafter-described purposes, and these are included in the technical scope of the present invention.

[0062] Following the usual smelting method, melt the steel with the chemical composition shown in Tables 1 to 3, after casting, hot forge after soaking (simulating the above-mentioned billet rolling) and cool to room temperature (cooling rate is 5°C / s ). Afterwards, reheat and carry out forging for the first time (simulation above-mentioned hot rolling for the first time), after cooling to forging temperature for the second time (simulation above-mentioned hot rolling for the second time), carry out forging for the second time and cool to room temperature ( The cooling rate was 5° C. / sec), and a...

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

This case hardened steel, which has favorable cold forgeability and superior impact properties after case hardening processing, contains C, Si, Mn, S, Cr, Al, Ti, Nb, B, and N, the remainder being iron and unavoidable impurities, precipitates that are at least 20 [mu]m2 among precipitates containing Ti and / or Nb have a number density of no greater than 1.0 precipitates / mm2, precipitates containing Mn and S that are over 5 [mu]m2 and less than 20 [mu]m2 among precipitates containing Ti and / or Nb have a number density of over 0.7 and no greater than 3.0 precipitates / mm2, and the fraction of ferrite is over 77 area%.

Description

technical field [0001] The present invention relates to case-hardened steel used as a raw material of machine parts which is subjected to surface-hardening treatment in transportation machines such as automobiles, construction machines, and other industrial machines, etc., and a method for manufacturing the same. Gears with shafts, etc.), shafts, bearings, and pulleys for CVTs, which exhibit excellent impact properties when subjected to surface hardening treatment, and exhibit excellent cold forgeability, and a manufacturing method thereof. Background technique [0002] Among mechanical parts used for automobiles, construction machinery, and various other industrial machines, surface hardening heat treatments such as carburizing, carbonitriding, and nitriding have traditionally been performed, especially for parts requiring high strength ( surface hardening treatment). In these applications, case-hardened steels such as SCr, SCM, and SNCM are generally used, which are regul...

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): C22C38/32C22C38/54B22D11/124B22D11/22C21D8/06
CPCC22C38/54C22C38/002C21D9/40C21D1/06C22C38/04C21D2211/005C21D2211/004B22D11/225C22C38/22C22C38/44C22C38/50C22C38/42C22C38/06C22C38/26C22C38/48C22C38/02C21D8/0226C21D8/005C21D8/0247C22C38/28C21D9/28C22C38/20C22C38/001C22C38/32B22D11/124C21D8/06
Inventor 冈本成朗永滨睦久
Owner KOBE STEEL LTD
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