Chapter 116 Dacromet, a legend in the surface treatment industry
The automotive industry is much more complex than many people imagine.
Especially with the strengthening of professional division of labor, the importance of the industrial chain has become higher and higher.
In later generations, due to the popularization of concepts such as "zero inventory", as long as one of the suppliers of various OEMs has parts supply problems, the OEMs will have to shut down the line.
As the main engine factory has shut down, those large supporting factories, such as seat factories, exhaust pipe factories, door panel and other parts manufacturers, basically have to stop production as well.
If the shutdown lasts for a few more days, 80% of the manufacturers in the entire industry chain will have to stop production.
Otherwise, the warehouse will be filled with production parts immediately, and there will not even be enough trolleys to install the parts.
So no matter what part it is, its importance is not low.
Not to mention important security parts related to safety performance such as wheel bolts.
"Liao Ke, what surface treatment process is Chaoyang Fastener Factory using now to process wheel bolts?"
It will definitely be difficult to make a decision before you understand the situation clearly.
Jiang Hui feels that the surface treatment process at Chaoyang Fastener Factory is most likely not good enough, so the corrosion resistance test cannot meet the requirements of the drawings.
Although he did not draw this drawing himself, he specifically gave instructions regarding the technical requirements for corrosion resistance.
What Liao Chengwen wants to modify now is probably the surface treatment requirements.
“Electro-galvanizing, most of the anti-rust treatments for bolts now are electro-galvanizing or hot-dip galvanizing.”
"This can be considered a method with relatively low cost and relatively mature technology."
Liao Chengwen must be familiar with common surface treatment technologies.
He is also the chief of the technical department after all.
“Is there any obvious problem with their electro-galvanizing production line?”
Electro-galvanizing is a relatively traditional surface treatment technology. If it is treated well, the anti-corrosion effect is actually good. Can.
Of course, this technology is definitely not the best corrosion-resistant surface treatment technology.
“The pre-treatment of electroplating is the basis for electroplating zinc and is also the key to ensuring product quality.”
“I went to confirm today whether Chaoyang Fastener Factory has done any pre-treatment before electroplating. The substrate to be plated must be processed to the specified requirements. ”
“After all, even if there are good plating solutions, appropriate plating parameters, equipment and highly skilled personnel to control the plating parameters, if there is no pre-treatment. Even if it is done well, it is impossible to obtain an electroplating layer that meets the quality requirements.”
“But the result I confirmed is that Chaoyang Fastener Factory has done a very good job in this regard, and there are no problems with the process.”
Liao Chengwen gave his judgment with certainty.
Before electro-galvanizing, remove the grease present on the base metal and foreign objects that affect the adhesion of the coating and other quality requirements, and remove the oxides on its surface at the same time, so that the surface of the wheel bolts has the specified cleanliness and certain activity. degree to ensure that the coating is firmly bonded to the substrate, which is the most basic requirement.
In most cases, there is no problem in this link, and electro-galvanizing is not prone to problems.
No matter what we do now, there is no way to meet the corrosion resistance requirements specified in the drawings. Liao Chengwen feels that there must be something wrong with the requirements of the drawings.
“Have you also confirmed that there are no problems with the process control of the electroplating process?”
It wasn't that Jiang Hui didn't believe Liao Chengwen, but he wanted to confirm the situation clearly before making next arrangements. "There is no problem. Their process flow is very clear. Each process has clear plating parameters. The concentration of the plating solution is also controlled. The workers also operate in accordance with the specifications."
"This kind of There should be no problems with the wheel bolts produced under such circumstances.”
Liao Chengwen once again emphasized the point that Chaoyang Fastener Factory has no problems.
There is no problem with the supporting factory, but the parts produced do not meet the corrosion resistance requirements on the drawings, then there must be something wrong with the drawings.
Jiang Hui naturally understood what Liao Chengwen meant.
“How many hours did white rust appear after their salt spray test?”
“About 10% of white rust appeared at about 120 hours, and at 240 hours There is slight red rust.”
“This test result is actually not bad, even slightly better than the corrosion resistance of the wheel bolts on the current BJ212.”
"The requirement that no red rust will appear for 960 hours as you mentioned is impossible for any domestic manufacturer to achieve."
Liao Chengwen gave his opinion quite firmly.
In this era, the most common surface treatments used in China’s various auto parts are electroplating and painting.
No matter which one it is, it is far from meeting Jiang Hui's requirements.
Don’t even say that no red rust will appear in the salt spray test for 960 hours, even if there is no red rust after 480 hours, it is impossible.
One can imagine how outrageous this request given by Jiang Hui seemed to Liao Chengwen!
Not to mention car parts, even the various bolts on military products such as tanks and artillery, the anti-corrosion requirements cannot meet the level Jiang Hui said.
“The previous drawings stipulated the various requirements that surface treatment needs to meet. As for the surface treatment process, it is marked electro-galvanizing or other surface treatment technologies of the same technical level. It is estimated that in addition to electro-galvanizing, everyone uses I have not tried other surface treatment processes to see if it is possible to meet the drawing requirements.”
“I accidentally saw a piece of information saying that a surface treatment technology expert in the United States developed a method using metal zinc sheets. Mainly, it is a highly dispersed water-soluble coating that simultaneously adds aluminum flakes, chromic acid, and deionized water as solvents. "
"This coating is stained on the metal substrate and is coated and baked in a fully closed circuit to form a thin film. Thin coating, they call it Dacromet coating "
"This coating can greatly improve the anti-corrosion requirements and innovate the shortcomings of traditional anti-corrosion life. "
"I think Chaoyang Fastener Factory can consider using Dacromet surface treatment technology to produce wheel bolts, and even some other bolts and nuts can also use this process."
Listen to Jiang Hui. As soon as he said that, Liao Chengwen couldn't help but frown.
If another college student who had just graduated a few months ago proposed a new surface treatment plan to him, he would definitely turn away without even wanting to listen to it.
But Jiang Hui said it in a convincing way. Even words like "Dacromet surface treatment", which are very difficult to pronounce, come up as words about advanced foreign surface treatment technology. It's easy to understand. He couldn't be more contemptuous.
"Xiaojiang, this Dacromet surface treatment process can really prevent the wheel bolts from showing red rust after 960 hours of salt spray testing?"
Even though it may be just an inconspicuous surface treatment technology, if it can really achieve the effect Jiang Hui said, it would be of absolutely extraordinary significance.
Liao Chengwen is obviously aware of this.
(End of this chapter)