JPS6039181A - Method for preventing surface roughening of stainless steel wire rod by pickling - Google Patents

Abstract

PURPOSE:To prevent the surface roughening a scalped and degreased austenitic stainless steel wire rod by dipping the wire rod in an aqueous soln. of sodium carbonate having a specified concn., subjecting the wire rod to soln. heat treatment, and pickling it. CONSTITUTION:An austenitic stainless steel wire rod is scalped and degreased. It is dipped in a 5-20% aqueous soln. of sodium carbonate contg. optionally <=50% sodium hydroxide. The dipped wire rod is subjected to soln. heat treatment, and it is pickled. Thus, the surface roughening of the wire rod is effectively prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing roughening of the austenitic stainless steel wire rod subjected to compound processing due to subsequent heat treatment and pickling.

In the production of austenitic stainless steel wire rods, in order to remove surface flaws that exist on the wire rods after rolling, the entire surface is often removed by naving, beering, or the like. After shaving, it is heat treated and pickled before being shipped.
Alternatively, it can be passed on to the next process such as drawing. However, products that have had their skin shaved often have rough skin due to pickling. This may be due to differences in local skin conditions that occurred during formulation, or
Depending on various factors, such as cutting oil not being completely removed in some areas and causing carburization, the scale adhesion may differ in some areas, resulting in unevenness on the surface due to pickling, or excessive pickling in some areas. , or may cause scale residue. Various preventive measures have been considered and implemented, but the one considered to be the most effective is the
This is the method proposed in 6-33472 (
Hereinafter referred to as the first-to-file invention method. ) This method of the prior invention does not involve removing the cutting oil after shaving the skin, but involves immersing the skin in a treatment solution consisting of a caustic soda aqueous solution or milk of lime, or a mixture of both at a concentration within a specific range. After it is deposited, it is subjected to post-heat treatment, and then pickled.

According to this method, the oxidized nucales produced by heat treatment become homogeneous, and a uniform pickling state is obtained by pickling with an artificial scale, so that unevenness or rough skin does not occur.

However, even the above-mentioned method of the invention of the prior application may not always work. For example, if the process from immersion in the processing solution to pickling is performed while the coil is wound, the processing solution components that dry and remain on the surface in the form of a film will melt at low temperatures during the heat treatment. The melting point of flowing caustic soda is 31
8°C) Scale accumulates in specific areas, especially in the contact areas between wire rods, and the scale in these areas becomes thicker, often leaving striped scales. This striped scale.

Too much removal reduces the efficiency of processing work, and also reduces the commercial value of the item as the removed marks become dented or the skin condition differs from other parts. Therefore, there has been a desire for a processing solution that does not have such drawbacks.

The present invention has been made in view of the above, and its gist is that austenitic stainless steel wire is treated with a compound, then degreased, and then treated with rehydrated sodium chloride or caustic soda for 50 minutes.
This is a pickling method for preventing rough skin of stainless steel wire rods, which is characterized by immersing the wire in a 5 to 20% aqueous solution of soda carbonate containing 0% U, followed by solution heat treatment, and then pickling.

That is, the inventors thought that the striped V residue caused by the above-mentioned aqueous solution of PI soda or the like could be solved by using an alkaline agent with a higher melting point.
As a result of testing various alkaline agents, we found that a small amount of caustic soda was added to an aqueous solution of soda or soda.
? It has been discovered that a mixed aqueous solution containing a and 1-1 is most suitable for this purpose. In this case, the concentration of the liquid is 5-2
0Φ is good, but even if it is 2 or less, the scale will be uneven. In addition, in the case of an aqueous solution in which caustic soda is mixed with soda carbonate, the amount of caustic soda should be 50% or less of the soda carbonate. If this is added to the liquid, the melting point will drop and it will melt and flow quickly during heating, resulting in poor results. In Table 1, 5TJ
Diameter of S304 +1. Shaved round wire coils of FF were treated with various treatment solutions including the method of the present invention and then subjected to solid solution treatment at 1010°C, then soaked in 13% sulfuric acid for 40 minutes, and then treated with ferric chloride as the main component. The results are shown when pickling was carried out by immersion in a pickling solution for 20 minutes.

Table 1: Results with various processing solutions As shown in Table 1, it can be seen that the method of the present invention is superior to conventional methods and comparative examples.

This confirms that even if the material is other austenitic stainless steel, or if the steel is subjected to skin shaving by peeling, the method of the present invention can produce sufficiently good results.

The reason why the method of the present invention provides such good results is that the melting point of soda carbonate is 852°C, which is close to 900°C, which is the point at which scale formation occurs on stainless steel, and the uniformity of the treatment agent film is maintained until then. Furthermore, it is presumed that the scale generation ability is appropriate according to the purpose of the present invention, and as a result, a uniform scale is generated.

As described above, the method of the present invention prevents roughening of the surface of austenitic stainless steel wire due to solution heat treatment and pickling after skin shaving, and is particularly effective when the wire is treated while being wound into a coil.

Claims (1)

[Claims] After the austenitic stainless steel wire is shaved, it is degreased, and then a 5-20% aqueous solution of soda carbonate or a 5-20% aqueous solution of soda carbonate containing 50% or less of caustic soda is applied.
% aqueous solution. A method for preventing pickling of stainless steel wire from roughening the surface of the stainless steel wire, which method is characterized by carrying out solution heat treatment and then pickling.