原油には腐食性物質,主に硫黄化合物が含まれます.高温で,これらの攻撃的な硫黄素を形成することができます.これに対抗するために, the reactor's internal surfaces are often protected by cladding—a layer of highly corrosion-resistant material (such as Type 347H stainless steel or specialized alloys) that is metallurgically bonded to the lower-cost材料の安全性と長寿の両方を保証します.
水処理装置では,熱い水素が鋼の壁に浸透し,炭素と反応し,メタンを形成し,内部裂け目と弱体化を引き起こし,水素攻撃として知られる現象を引き起こします. Manufacturers utilize specific alloy compositions (Cr-Mo steel) as dictated by the Nelson Curves to ensure the steel can safely operate under the specific combination of temperature and hydrogen partial pressure.