Supervisor, Lukens Steel Company, Coatesville, Pa.
Pages: 23 Published: Jan 1982
The operating conditions of coal liquefaction and petrochemical pressure vessels require heavy-gage 2¼-Cr-1Mo steel for which only limited data exist. A program was initiated to determine the effects of heat treatment and composition on the tensile and impact properties of 260- to 300-mm-thick 2¼Cr-1Mo steel. This work is the result of that study.
Commercial heats were produced with a variety of modifications in melting practice to obtain different levels of silicon, sulfur, phosphorus, and tin, and to modify the shapes of inclusions. Plates were rolled from large ingots, heat treated, and tested. Testing included room-temperature and elevated-temperature tension tests, and Charpy V-notch (CVN) tests for base condition toughness and for measuring the resistance to temper embrittlement.
Data are presented to show that low sulfur and a fine-grain size are important for improving base-notch toughness, and silicon, manganese, and phosphorus control are necessary to improve the resistance to temper embrittlement. Also, it is necessary to accelerate cool after austenitizing to achieve acceptable toughness levels and SA387-22 Class 2 properties.
heavy gage, notch toughness, chromium-molybdenum steels, residual elements
Paper ID: STP28415S