High-strength galvanized steel sheet, and method for manufacturing same

A technology of galvanized steel sheet and manufacturing method, applied in the direction of manufacturing tools, chemical instruments and methods, hot-dip plating process, etc., can solve the problems of hydrogen not easy to release, intrusion, hydrogen embrittlement, easy residual hydrogen, etc., and achieve hydrogen embrittlement resistance excellent effect

Active Publication Date: 2020-07-17
JFE STEEL CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007]However, in general, when Zn, Ni, etc. are plated, hydrogen is not easily released from the material and penetrates, so hydrogen in steel called diffusible hydrogen tends to remain. , prone to hydrogen embrittlement of billets

Method used

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  • High-strength galvanized steel sheet, and method for manufacturing same
  • High-strength galvanized steel sheet, and method for manufacturing same
  • High-strength galvanized steel sheet, and method for manufacturing same

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0128] Molten steels having the compositions shown in Table 1 were melted in a converter, and slabs were produced in a continuous casting machine. This slab was heated to 1200°C, and a hot-rolled coil was produced at a finish rolling temperature of 840°C and a coil coiling temperature of 610°C. The hot-rolled coil was made into a cold-rolled billet having a plate thickness of 1.4 mm at a cold reduction rate of 50%. The cold-rolled billet was heated to 810°C (within the range of (Ac3 point -20°C) to 900°C) through annealing treatment with a hydrogen concentration of 9 vol% and an atmosphere in an annealing furnace with a dew point of -30°C, stayed for 60 seconds, and cooled To 500°C, stay for 50 seconds. Afterwards, galvanizing is carried out, alloying treatment is performed, and after plating, it is cooled to below 100°C in a water tank with a water temperature of 40°C, and the average cooling rate is set to 3°C / s to manufacture high-strength alloyed galvanized steel sheets (...

Embodiment 2

[0139] The molten steel with the composition shown in Table 2 was smelted in a converter, and after being made into a slab by a continuous casting machine, hot rolling, cold rolling, heating (annealing), pickling, pickling, (When "○" is shown in Table 2, the HCl concentration of the pickling solution is adjusted to 5mass%, and the solution temperature is adjusted to 60°C before use.) Perform annealing and plating treatment, temper rolling, width trimming, and post-heat treatment , Manufacture 1.4mm thick high-strength galvanized steel sheet (product sheet). In addition, cooling (cooling after a plating process) passed through the water tank of 40 degreeC of water temperature, and cooled to 100 degreeC or less.

[0140] Take the sample of the galvanized steel sheet obtained above, and use the following method to observe the steel structure and perform a tensile test, measure and calculate the structure fraction (area ratio), yield strength (YS), tensile strength (TS), Yield st...

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Abstract

Provided are: a high-strength hot-dip galvanized steel sheet that has a material quality meeting the high yield strength highly demanded for ultra-high-strength plated steel sheets for which hydrogenembrittlement is a concern, has an excellent plating appearance and excellent hydrogen embrittlement resistance, and has high yield strength suitable for building materials and automotive impact-resistant parts; and a method for manufacturing the same. This high-strength galvanized steel sheet comprises: a steel sheet having a specific component composition and a steel structure that contains at least 70% (including 100%) martensite and bainite, less than 20% (including 0%) ferrite, and less than 5% (including 0%) residual austenite, and having an in-steel diffusible hydrogen content of no more than 0.20 mass ppm; and a galvanized layer formed on the surface of the steel sheet and having an Fe content of 8 to 15%, in mass%, and a plating adhesion amount per surface of 20 to 120 g / m2, wherein the amount of Mn oxide contained in the galvanized layer is no more than 0.050 g / m2, the tensile strength is at least 1,100 MPa, and the yield ratio is at least 0.85.

Description

technical field [0001] The present invention relates to a high-strength galvanized steel sheet that is excellent in resistance to hydrogen embrittlement and is suitable for building materials and crash-resistant parts of automobiles, and a method for producing the same. Background technique [0002] Nowadays, the improvement of the crash safety and fuel consumption of automobiles is strongly demanded, and the strengthening of steel sheets used as parts materials has been progressing. Among them, from the viewpoint of ensuring the safety of occupants in the event of a car collision, material materials for parts used around the passenger compartment require not only high tensile strength but also high yield strength. In addition, automobiles are widely used around the world, and automobiles are used for various purposes in various regions and climates. Therefore, high rust resistance is required for steel sheets used as component materials. As documents related to characteris...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C38/00C21D9/46C22C38/06C22C38/60C22C18/00C22C18/02C23C2/06
CPCC21D9/46C22C38/06C22C38/60C23C2/06C21D1/76C21D8/0226C21D8/0236C21D8/0242C21D8/0247C21D9/561C21D2211/001C21D2211/002C21D2211/005C21D2211/008C22C38/02C22C38/04C22C38/08C22C38/12C22C38/14C22C38/16C22C38/38C23C2/02C23C2/28C23C2/40C23C2/261C23C2/29C23C2/024C23C2/26C23C2/0224C22C38/001C22C18/02C21D8/0273C22C38/002C22C38/008C22C38/20C23C2/12C23G1/00C22C38/22C22C38/26C22C38/40C22C38/44C22C38/18C22C38/46C22C38/24C22C38/54C22C38/28C22C38/32C22C38/50C22C38/48C22C38/42Y10T428/2495C23C2/04C21D9/562B32B15/01Y10T428/264C23C30/005Y10T428/12799Y10T428/12951C21D9/5735Y10T428/12972B32B15/013Y10T428/263B32B15/18C23C30/00Y10T428/12958C21D8/0221C21D9/573B32B15/043C21D8/0263Y10T428/265B32B15/04Y10T428/27Y10T428/26Y10T428/24967
Inventor 吉富裕美冲田泰明木庭正贵小野义彦松田广志
Owner JFE STEEL CORP
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