DE742409C

DE742409C - Procedure for testing the degree of fluidity of metals

Info

Publication number: DE742409C
Application number: DER114060D
Authority: DE
Inventors: Dr-Ing Wolfram Ruff
Original assignee: WOLFRAM RUFF DR ING
Current assignee: WOLFRAM RUFF DR ING
Priority date: 1942-09-18
Filing date: 1942-09-18
Publication date: 1943-12-02

Description

Verfahren zur Prüfung des Flüssigkeitsgrades von Metallen Zur Bestimmung des Flüssigkeitsgrades von Metallen sind bereits Verfahren bekanntgeworden, be denen das Metall in dem Laufkanal einer Gießform zur Erstarrung kommt und die Lauflänge gemessen wird. Die Metalle vermögen in solchen Formen einen langen Weg zurückzuegen., Im allgemeinen ist es aber schwierig, die Formen mit leinem einwandfreien langen Laufkanal von gleichbleibendem Querschnitt zu versehen, an dessen Anfang und Ende sich vergleichbare Strömungsbedingungen aufrechterhalten lassen.Method for testing the degree of fluidity of metals For determination the degree of fluidity of metals processes are already known, be which the metal solidifies in the runner of a casting mold and the run length is measured. Metals can come a long way in such forms., In general, however, it is difficult to produce the shapes with a flawless length To provide a running channel of constant cross-section, at its beginning and end comparable flow conditions can be maintained.

Um die Bestimmung des Flüssigkeitsgrades eines Metalls zu vereinfachen, weist die vorliegende Erfindung einen neuen Weg. Nach dem neuen Verfahren wird Seine Gießform mit derart kurzem und engem Laufkanal verwendet, daß das zu prüfende Metall zunächst aus dem Kanal herausläuft, aber noch während seines Laufes durch Erstarren des Metalls von den Seitenwänden her innerhalb des Laufkanals abgeschnürt wird, worauf die kurz vor der Abschnürung aus der Gießform ausgetretene metallmenge als maß des Flüssigkeitsgrades gewogen wird. Die Gießform braucht also bei diesem neuen Verfahren nur so lang zu sein, daß bei dem geringsten jeweils zulässigen Flüssigkeitsgrad das zu untersuchende Metall gerade noch austritt. To simplify the determination of the degree of fluidity of a metal, the present invention shows a new way forward. According to the new procedure, his will be Casting mold with such a short and narrow channel used that the metal to be tested initially runs out of the canal, but still during its course by solidification of the metal is pinched off from the side walls inside the channel, whereupon the amount of metal that emerged from the mold shortly before the constriction was identified as measure of the degree of fluidity is weighed. So the mold needs with this new one Procedure to be only so long that with the lowest permissible degree of fluidity the metal to be examined just emerges.

Eine derartige Änderung der bisher angewendeten Verfahren ist möglich, weil xnzwischen festgestellt wurde, daß das Laufvermögen eines flüssigen Metalls in einem Karal weniger von dem Verhalten der vordersten Strömungsspitze als vielmehr von der Abschnürgeschwindigkeit im Anfangsteil des Strömungskanals abhängig ist. Durch Verengung des Strömungskanals bereits in der Nähe des Eingußtrichters durch Ansetzen des flüssigen Metalls an den Formwandungen wird das Weiterfließen des Metalls stärker und früher beeinflußt als durch die Temperaturabnahme an der Strömunggsspitze. Durch eine Speisung der Strömungsspitze immer wieder mit besonders heißem Metall aus der Kanalmitte bei vor ihr noch vollständig offenem Kanalquerschnitt mag dies eine leichte Erklärung finden. Such a change in the previously used procedures is possible, because it has since been found that the runnability of a liquid metal in a Karal less from the behavior of the foremost current tip than more depends on the constriction speed in the initial part of the flow channel. By narrowing the flow channel already in the vicinity of the pouring funnel Attachment of the liquid metal to the mold walls will prevent the metal from flowing influenced more and earlier than by the decrease in temperature at the top of the flow. By repeatedly feeding the flow tip with particularly hot metal from the middle of the canal in front of her still complete open duct cross-section may this find an easy explanation.

Claims

In practice, the shortening of the canal results in the to determine the degree of fluidity of a metal required casting mold with the Catching and weighing of the spilled metal amounts against previously significant advantages. When tracking the running ability z. B. of steel became the total length of previously according to patent 660 166 the usual sand mold shortened from 800 to 275 mm; in order to the mold weight decreased by more than 500/0. This involves the production of the short runway with a small shape model, of course, much easier than with the long one. The short ones Molds also only take up a small amount of space when drying and storing and are significantly less sensitive to damage of any kind. another The short molds are also more advantageous when they are poured. now the smelter gains an overview of his casting result when taking samples without breaking the mold; earlier he had to wait until they were carried away and smashed was. The quicker overview of his result reveals errors in the sampling process all the more easily and thus saves him a considerable amount of time for new work.

PATENT CLAIM: Method for testing the degree of fluidity of Metals using a casting mold with a running channel, characterized in that that a mold with such a short and narrow channel is used that the Metal to be tested first runs aws out of the canal and then solidifies in the canal is constricted from the side walls, after which the degree of fluidity on the basis of before this constriction, the amount of metal that has leaked, caught and weighed is assessed will.

To distinguish the subject of the application from the state of the art are no publications were considered in the granting procedure.