<SUBMISSION>
<ACCESSION-NUMBER>0001790982-20-000056
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20200403
<FILING-DATE>20200407
<DATE-OF-FILING-DATE-CHANGE>20200407
<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>20780667
</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>2020-04-03</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>2020-04-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>4776</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>8.06</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>46450</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents vested restricted stock units granted pursuant to the Arconic Corporation 2020 Stock Incentive Plan in respect of the reporting person's deferral of Howmet Aerospace Inc.'s (former Parent Company) director fees.  The deferred fee amount of $38,500 was converted into deferred restricted stock units based on the closing price of Arconic Corporation common stock on April 3, 2020.</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. In connection with the Separation, all equity awards held by the reporting person with respect to Arconic Inc.'s common stock as of the Separation will be adjusted to relate to Arconic common stock in a manner intended to preserve the aggregate intrinsic value of the original award. The amount of securities reported on this Form 4 do not reflect such adjustment, to the extent applicable, and this Form 4 will be amended in a subsequent filing to reflect such adjustment.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Diana Toman  (CLO and Corporate Secretary), by power of attorney</signatureName>
        <signatureDate>2020-04-07</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
