PL152701B2 - Heat resisting nickel based alloy - Google Patents

Description

PATENT DESCRIPTION

Additional patent to patent no. - Filed: 89 03 03 (P. 278085)

Priority _____

Application announced: 89 12 27

Patent description published: 1993 1130

152 701

Int. Cl. ⁵ C22C 19/05 great * GÓLSA

Creators of the invention: Konrad Fiałkowski, Władysław Markiewicz, Wacław Ptak, Stanisław Rudnik, Zygmunt Szołucha, Roman Wielgosz, Andrzej Zajłuż

The holder of the patent: Politechnika Krakowska im. Tadeusza Kościuszko, Krakow (Poland)

HEAT RESISTANT ALLOY ON A NICKEL BASE

The subject of the invention is a heat-resistant nickel-based alloy intended for the seat of exhaust valves of internal combustion engines.

The exhaust valves of internal combustion engines operate at high temperatures, are exposed to temperature shocks, corrosive and erosive effects of exhaust gases, and quite significant mechanical loads. For this reason, it will stick - the closing surfaces of the exhaust valves are welded with heat-resistant alloys.

The high-percentage nickel alloy intended for surfacing, known from Polish patent specification No. 114 823, contains more than 70% by weight of nickel, and the hardening components are silicon in the amount of up to 5% and carbon in the amount of up to 2%. This alloy also contains impurities in the form of phosphorus and sulfur in the amount of up to 0.1% and deoxidizing components such as manganese up to 2% and aluminum up to 5%, and additionally 0.2 - 3.5ϊ bar.

Cobalt-based alloys have a similar purpose. Known from Polish patent specification No. 112 646, the cobalt alloy intended for surfacing contains 0.3 - 2.5% by weight of carbon, 0.5 - 2% silicon, 3 - 15% tungsten, 10 - 30% chromium, 40 - 65% cobalt , up to 1.5% of manganese, up to 0.1% of aluminum, up to 3% of iron, 0.2 - 2% of barium and impurities in the form of phosphorus and sulfur up to 0.1%.

The disadvantage of the known alloys intended for surfacing with them on the faces of exhaust valves, caused by the constantly increasing shortage of individual components, is the necessity to use very expensive elements such as boron and cobalt in the production of these alloys.

The invention makes it possible to develop an alloy composition equivalent to the properties of the alloys known to date, while eliminating expensive components.

152 701

152 701

The alloy according to the invention contains 1.1 - 1.3% by weight of carbon, 0.3 - 0.5% of silicon, 29 - 32% of chromium, 7-8% of tungsten, 1.7 - 2% of aluminum, the rest being nickel and the inevitable pollution. The maximum total silicon and aluminum content is 2.3%.

The alloy according to the invention is a heat-resistant alloy with good properties. It can be used to make seat on exhaust valves using known technological steps. The proposed alloy can be used as an equivalent, cheap alloy in relation to the cobalt-based and boron-nickel-based alloys.

The subject of the invention is illustrated in detail in the following examples.

Example 1 The alloy contains by weight: 1.15% C, 30.8% Cr, 7.5% W, 0.40% Si, 1.89% Al, the rest being nickel and the inevitable impurities. The melting point (liquidus) is 1602 K, and the difference between the liquidus and solidus temperatures is 320 K.

Example II. The alloy contains by weight: 1.10% C, 29.8% Cr, 7.4% W, 0.36% Si, 1.72% Al, the rest being nickel and the inevitable impurities. The melting point (liquidus) is 1591K, and the difference between the liquidus and solidus temperatures = 327 K.

Claims (1)

Patent claim A heat-resistant alloy based on a matrix containing 1.1 - 1.3% by weight of carbon, 0.3 - 0.5% by weight of silicon, as well as chlorine and aluminum, containing 29 - 32% by weight of chromium, 7-8% by weight of tungsten, 1 7 - 2% aluminum, the rest is nickel and unavoidable impurities, with the maximum total silicon and aluminum content being 2.3%. Department of Publishing of the UP RP. Circulation of 90 copies. Price: PLN 10,000