<SUBMISSION>
<ACCESSION-NUMBER>0001790982-20-000148
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20200701
<FILING-DATE>20200706
<DATE-OF-FILING-DATE-CHANGE>20200706
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>ONEAL E STANLEY
<CIK>0001182337
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-39162
<FILM-NUMBER>201013855
</FILING-VALUES>
<MAIL-ADDRESS>
<STREET1>MERRILL LYNCH CORPORATE SECRETARY
<STREET2>222 BROADWAY, 17TH FLOOR
<CITY>NEW YORK
<STATE>NY
<ZIP>10038
</MAIL-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>Arconic Corp
<CIK>0001790982
<ASSIGNED-SIC>3350
<IRS-NUMBER>842745636
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>201 ISABELLA STREET
<CITY>PITTSBURGH
<STATE>PA
<ZIP>15212-5872
<PHONE>(412) 992-2500
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>201 ISABELLA STREET
<CITY>PITTSBURGH
<STATE>PA
<ZIP>15212-5872
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>Arconic Rolled Products Corp
<DATE-CHANGED>20191011
</FORMER-COMPANY>
</ISSUER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-07-01</periodOfReport>

    <issuer>
        <issuerCik>0001790982</issuerCik>
        <issuerName>Arconic Corp</issuerName>
        <issuerTradingSymbol>ARNC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001182337</rptOwnerCik>
            <rptOwnerName>ONEAL E STANLEY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>201 ISABELLA STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 200</rptOwnerStreet2>
            <rptOwnerCity>PITTSBURGH</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>15212</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-07-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1785</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>13.23</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>113204</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents restricted stock units (RSUs) granted to the reporting person as a result of his previous election to participate in the Arconic Corporation 2020 Deferred Fee Plan for Directors.  The number of RSUs granted was calculated based on the amount of retainer payable and the closing price on the date the retainer was paid to directors.</footnote>
        <footnote id="F2">On April 1, 2020, Arconic Inc. completed the separation of its business into two independent, publicly-traded companies (the Separation): Howmet Aerospace Inc. and Arconic Corporation. The number of shares and share equivalents reported on this Form 4 reflects an adjustment for the elimination of fractional shares and share equivalents related to equity awards granted prior to the conversion of such awards in connection with the Separation.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Adam Wheeler (Assistant General Counsel and Assistant Corporate Secretary), by power of attorney</signatureName>
        <signatureDate>2020-07-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
