INFLUENCE OF ARTILLERY WEAPON BARREL SUPERHEAT ON ABRASION WEAR RESISTANCE OF MATERIAL

This paper studies the influence of the artillery weapon barrel superheat on abrasion wear resistance of material. The firing process has a compound mechanical, thermal and chemical effect on the barrel. Many wear mechanisms exist in the barrel in firing conditions: abrasion, adhesion, fatigue and tribocorrosion. This paper presents the procedure and the results of abrasion wear experiment. Some test samples were previously tempered and air cooled. The abrasion test samples were made of the heat treated steel 42CrMo4. Wear resistance is represented by the sample mass loss during the wear process. The test results show that unheated samples exhibit higher wear resistance in comparison with heated samples. A significant material wear increase of 43% is shown in the samples which were heated at 900 degree C. Conclusively, the test results show that excessive fire causes the weapon barrel to superheat and the material wear resistance to significantly decrease.Original Abstract: U ovom se radu istrazuje utjecaj pregrijavanja cijevi topnickog oruzja na abrazijsko trosenje materijala. Proces opaljenja ima slozeno mehanicko, toplinsko i kemijsko djelovanje na cijev oruzja. Visestruki mehanizmi trosenja javljaju se u cijevi tijekom opaljenja: abrazija, adhezija, umor povrsine i tribokorozija. Rad prikazuje postupak i rezultate ispitivanja abrazijskog trosenja. Neki od ispitnih uzoraka su prethodno zagrijavani i hladeni na zraku. Ispitni uzorci su izradeni od celika 42CrMo4. Otpornost na trosenje je predstavljena gubitkom mase uzoraka tijekom trosenja. Rezultati istrazivanja pokazuju da nezagrijavani uzorci imaju vecu otpornost na trosenje u usporedbi sa zagrijavanim uzorcima. Znacajan porast trosenja materijala od 43% u odnosu na nezagrijavane uzorke ostvaren je kod uzoraka koji su prethodno zagrijavani na 900 degree C. Zakljucno, rezultati istrazivanja pokazuju da rezim paljbe ne smije biti prekoracen, jer on dovodi do pregrijavanja cijevi i do smanjenja otpornosti materijala na trosenje.