Restoration of continuous casting machine mold copper plates made of Cr–Zr bronze using multi-pass friction stir lap welding-Reference-Cited by-同舟云学术

Restoration of continuous casting machine mold copper plates made of Cr–Zr bronze using multi-pass friction stir lap welding

Published:2024-01-04 Issue:6 Volume: Page:66-83
ISSN:2412-8783
Container-title:Izvestiya. Non-Ferrous Metallurgy
language:
Short-container-title:Izv.VUZ. Tsvet. Met.

Author:

Makarov A. V.¹^ORCID,Lezhnin N. V.¹^ORCID,Kotelnikov A. B.²^ORCID,Vopneruk A. A.²^ORCID,Korobov Yu. S.³^ORCID,Valiullin A. I.¹^ORCID,Volkova E. G.¹^ORCID

Affiliation:

1. M.N. Mikheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences

2. R&D Enterprise “Mashprom”

3. M.N. Mikheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences; Ural Federal University named after the First President of Russia B.N. Yeltsin

Abstract

An innovative technology has been developed and implemented for the restoration and manufacturing of new mold copper plates for continuous casting machines (CCMs) using wear-resistant composite coatings. These copper plates significantly surpass the service life of imported copper plates featuring galvanic coatings, sometimes by up to 20 times. However, the pressing challenge of restoring the copper plates of molds once they have reached the minimum permissible thickness remains unresolved. This study aimed to explore the feasibility of restoring a plate composed of precipitation-hardening Cr–Zr bronze with the same material by employing friction stir lap welding (FSLW). The objectives were to examine the structure, quality, and hardness of the welded joint, alongside investigating the impact of heat treatment (quenching and aging). By utilizing multi-pass FSLW method with a rotating tool crafted from a heat-resistant alloy and overlapping (partially overlapping) successive passes, a welded joint with a thickness of ~5 mm was achieved, devoid of critical continuity flaws (cracks or voids). Within the bronze layer restored through FSW, a softening effect ranging from 85–105 HV1 was observed compared to the initial hardness of the bronze in its hardened and aged state while in service (116–126 HV1). This is attributed to recrystallization and overaging, specifically the coarsening of chromium particles within the Cr–Zr bronze due to the heating of the weld nugget (stir zone) to 600–700 °C. The observed softening effect during FSW can be effectively rectified through heat treatment involving dissolution of the hardening phases followed by aging, resulting in a hardness increase to approximately 120–150 HV1. The process of restoring copper plates to their original thickness via the progressive and environmentally friendly FSW method, followed be the subsequent application of wear-resistant composite coatings, presents the opportunity for an almost infinite operational cycle of molds. This advancement could potentially eradicate the necessity for Russia to rely on importing such molds copper plates.

Publisher

National University of Science and Technology MISiS

Subject

Metals and Alloys

Reference46 articles.

1. Kotelnikov A.V., Vopneruk A.A., Makarov A.V., Korobov Yu.S., Kirichkov A.A., Dagman A.I., Shefrin I.N. New materials and technologies for significantly increase the wear resistance of the working surface of metallurgical equipment. Tyazheloe mashinostroenie. 2018;(9):14—20. (In Russ.).

2. Vdovin K.N., Pozin A.E. Cavitation wear of coated copper walls of molds. Stal’. 2018;(9):14—20. (In Russ.).

3. Kushnarev A.V., Kirichkov A.A., Vopneruk A.A., Kotelnikov A.V., Korobov Yu.S., Makarov A.V., Filatov S.V., Shefrin I.N. Physico-mechanical characteristics of thermal sprayed coatings on the walls of the mold of continuous casting machines. Svarka i diagnostika. 2017;(5):50—53. (In Russ.).

4. Korobov Yu.S., Kotelnikov A.B., Kushnarev A.V., Kirichkov A.A., Filippov M.A., Vopneruk A.A. Analysis of the features of the formation of thermal sprayed coatings on the wall slab crystallizer. Chernye metally. 2017;(1): 41—45. (In Russ.).

5. Makarov A.V., Soboleva N.N., Malygina I.Yu. Role of the strengthening phases in abrasive wear resistance of laser-clad NiCrBSi coatings. Journal of Friction and Wear. 2017;38(4): 272—278.