6-K

FORM 6-K

U.S. SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE

SECURITIES EXCHANGE ACT OF 1934

Dated November 10, 2022

Commission File Number 1-14878

GERDAU S.A.

(Exact Name as Specified in its Charter)

N/A

(Translation of Registrant’s Name)

Av. Dra. Ruth Cardoso, 8,501 – 8° andar

São Paulo, São Paulo - Brazil CEP 05425-070

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F.

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ¨

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ¨

Indicate by check mark whether by furnishing the information contained in this Form, the registrant is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.

If “Yes” is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b): Not applicable.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused the Report to be signed on its behalf by the undersigned, thereunto duly authorized.

Date:  November 10, 2022

Exhibit 99.1

GERDAU S.A.

CNPJ nº 33.611.500/0001-19

NIRE 35300520696

NOTICE TO THE MARKET

Gerdau S.A. (B3: GGBR / NYSE: GGB) and Metalúrgica Gerdau S.A. (B3: GOAU) (collectively, the “Companies”), making reference to the Material Fact published by Gerdau S.A. on June 13, 2018, informs that on November 8, 2022, the First Panel of the Superior Court of Justice unanimously granted the Special Appeal filed by Gerdau S.A., granting the annulment of the conviction imposed by the Administrative Council for Economic Defense on Gerdau S.A., for anticompetitive practices.

The Superior Court of Justice decision imposes on the Administrative Council for Economic Defense the observance of due process of law, to the extent that it considers relevant the economic evidence, initially ignored, for the (non) establishment of a cartel. The execution of the fine imposed by the autarchy was suspended due to an injunction that authorized Gerdau to offer a guarantee insurance.

This decision has not yet been formalized through the competent court ruling.

More information is available in Note #15 of the Company's September 30, 2022 Financial Statements.

Gerdau considers that this decision proves the appropriateness of its business practices, which are and always have been based on the principles of transparency and free competition, consolidated throughout its 121-year history in Brazil.

São Paulo November 9, 2022.

Rafael Dorneles Japur

Executive Vice-President

Investor Relations Officer

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