Lexicon
H
Hard (metal) alloys
are composed mainly of (up to 95%) highly enamelled, very hard carbides, either of one carbide type or of a carbide of varying types (W, Ti, Ta, Nb). Furthermore chrome or boron carbide as well as compounds of hard materials with nitrogen may be present. The remainder is binder phase, Fe, Co or Ni. Co is the most used. Whereas carbide increases the abrasion resistance and cutting property, the binder phase creates a certain toughness and bending strength. These alloys are produced through pulverisation. Binding phase and hard materials are mixed to a powder. The powder is then pressed and sintered at temperatures higher than the melting point of the binding phase. The structure then has the appearance of rolled balls of carbide, with a binding phase filling.
Hedging
Hedging is to reduce the risk involved with interest rates and price fluctuations. Losses on the cash market should be compensated by profits on the futures market. A future contract is a binding agreement between two parties to buy or sell, and therefore receive or deliver a definite amount and a certain type of product at a fixed contract date at a fixed price A ‘long’ position obliges the buyer to pay the agreed price at maturity of the contract and to accept delivery. The corresponding ‘short’ position obliges the seller to delivery at maturity of the futures contract and to accept the agreed payment of the goods.
High Speed Steel
An alloyed high grade steel, part of the tool steel group, belonging to the steel group 32 (with Co) and 33 (without Co) (DIN EN 10 027-2). Characterised by the alloys Cr, W, Mo and V, and, if applicable, Co. High Speed Steel is extremely hard and tough, highly corrosion resistant and has a keen cutting ability, therefore suitable for tool making, also being able to adjust to temperature changes. The chemical property and heat control of this steel gives it its consistency and ability to take temperatures of 600°C. Because of their toughness, only carbides and oxide ceramics have better cutting abilities than high speed steel. They are used for metal cutting tools. DIN 17 350, EN 10020.
High temperature Steel
Is a austenite steel with very low C-content, at least 13% Cr, high Ni content easily more than 10% even up to 34%. These steels have good strength durability at temperatures between 550°C and 600°C, even under long-term mechanical stress. Two types of alloys >20% Chrome and >30% Nickel have this property even at temperatures of 900° to 1000°C. DIN 17459 pertains to circular tubes, DIN 17460 to sheets, coils, rods and forgings. Used mainly in building power stations where normal temperature steel (DIN 17175 and 17177) is not enough. Normal temperature and high temperature steel are standardised in DIN 17240 for screws and nuts.
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