Nippon Steel Corporation

Hirohide Muraoka

Naoki Saitoh

Tatsuya Kumagai

Seinosuke Yano

Yoshihiro Okamura

Katsumi Kurebayashi

The present invention provides an abrasion resistant steel having a hardness of HB400 to HB520, having little change of hardness during long term use, and superior in toughness, characterized by containing, by mass %, C: 0.21% to 0.30%, Si: 0.30 to 1.00%, Mn: 0.32 to 0.70%, P: 0.02% or less, S: 0.01% or less, Cr: 0.1 to 2.0%, Mo: 0.1 to 1.0%, B: 0.0003 to 0.0030%, Al: 0.01 to 0.1%, and N: 0.01% or less, further containing one or more of V: 0.01 to 0.1%, Nb: 0.005 to 0.05%, Ti: 0.005 to 0.03%, Ca: 0.0005 to 0.05%, Mg: 0.0005 to 0.05%, and REM: 0.001 to 0.1%, having a balance of Fe, and furthermore having an ingredient with an M value defined by the following formula (1) of &#x2212;10 to 16:=26&#xd7;[Si]&#x2212;40&#xd7;[Mn]&#x2212;3&#xd7;[Cr]+36&#xd7;[Mo]+63&#xd7;[V]&#x2003;&#x2003;(1)

High toughness abrasion resistant steel with little change in hardness during use and method of production of same

A process for producing steel possessing a high level of toughness and strength free of anisotropy and having good resistance to stress corrosion cracking in seawater conditions comprises the steps of:

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Tokai, Japan

Hirohide Muraoka