Title:
MANUFACTURING METHOD FOR HOT FORGING-FORMED, COMPOSITE-QUENCHED AND STRUCTURE-REFINED HIGH-STRENGTH BOLT
Document Type and Number:
WIPO Patent Application WO/2023/184782
Kind Code:
A1
Abstract:
Disclosed in the present invention is a manufacturing method for a hot forging-formed, composite-quenched and structure-refined high-strength bolt. The manufacturing method comprises hot forging forming and complete quenching, critical zone quenching, tempering, thread rolling, surface phosphorization and a blackening treatment, and specifically comprises: firstly, induction heating a bolt steel bar to 920-1000ºC, carrying out heat preservation followed by hot forging forming, and controlling the final forging temperature to be 830-850ºC; immediately quenching the bolt by using residual heat after forging, and then cooling the bolt; after the bolt is cooled to room temperature, re-heating the bolt to 760-790ºC, carrying out heat preservation followed by oil quenching and cooling; then heating the bolt to 350-500ºC for tempering treatment, and carrying out heat preservation and air cooling on the bolt; and finally, carrying out a post-treatment step. The bolt prepared by means of the preparation method of the present invention has a high strength and a high toughness, wherein the obtained bolt has a tensile strength of larger than or equal to 1100 MPa, an elongation after fracture of larger than or equal to 12%, a reduction of area of larger than or equal to 60%, and a -20ºC ballistic work of larger than or equal to 85 J.
Inventors:
LI HAIYANG (CN)
XU XIAOCHUN (CN)
CHEN XINGHUA (CN)
ZHOU LEI (CN)
WU MENG (CN)
BAO YUKUN (CN)
DENG WEI (CN)
XU XIAOCHUN (CN)
CHEN XINGHUA (CN)
ZHOU LEI (CN)
WU MENG (CN)
BAO YUKUN (CN)
DENG WEI (CN)
Application Number:
PCT/CN2022/105188
Publication Date:
October 05, 2023
Filing Date:
July 12, 2022
Export Citation:
Assignee:
NANJING IRON & STEEL CO LTD (CN)
International Classes:
C21D1/25; B23P15/00; C21D1/42; C21D6/00; C21D8/00; C21D9/00; C22C38/02; C22C38/04; C22C38/20; C22C38/22; C22C38/42; C22C38/44
Foreign References:
| CN111155031A | 2020-05-15 | |||
| CN110257595A | 2019-09-20 | |||
| CN102152078A | 2011-08-17 | |||
| CN106167881A | 2016-11-30 | |||
| CN111394661A | 2020-07-10 | |||
| CN102943207A | 2013-02-27 | |||
| CN102851479A | 2013-01-02 | |||
| CN108018503A | 2018-05-11 | |||
| JP2020084276A | 2020-06-04 |
Attorney, Agent or Firm:
NANJING SUGAO PATENT AND TRADEMARK FIRM ( ORDINARY PARTNERSHIP ) (CN)
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