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Chapter 100 Recurrence of the accident
At this time, Zheng Xuewen put down the blade and magnifying glass in his hand, and said loudly, "Everyone, calm down and stop arguing."

He is the deputy director of the Engineering Technology Department, and he still has a strong personality. The originally extremely noisy scene gradually quieted down.

Zheng Xuewen said, "I think Xiao Lin's deduction should be correct."

what!
Minister Zheng actually agreed with Lin Feng's inference!

This, this, this.
Originally there were doubts, but now all that is left is stunned, they can't accept it, how did Minister Zheng agree with Lin Feng's inference, could it really be the problem of No.

The people in the tooling design department even looked at each other in blank dismay, praying in their hearts, it must not be a problem with the broach design, otherwise, they will lose face.

Zheng Xuewen continued to speak loudly, "I just took a magnifying glass to carefully look at the small groove on the tenon of the blade. What Xiaolin said is right. This groove is really made by a broach. The bottom of the groove There's even rounding."

After finishing speaking, Zheng Xuewen suggested, "In order to see more clearly, I suggest going to the metallographic analysis room, where there is a microscope, and magnifying the groove a hundred times, or two hundred times, then you can see it more clearly."

Wang Tianfang decided, "Then let's go to the metallographic analysis room now."

At least half of the group of people left in a hurry, and went out of the blade workshop to the metallographic analysis room together. The rest of the people stayed here temporarily, and the metallographic analysis room could not be crowded if there were too many people at once.

The distance is not far, and it takes about five or six minutes to arrive at the metallographic analysis room. This is a department under the Engineering Technology Department. It usually mainly conducts metallographic analysis on various metal materials. There are various microscopes, and even tens of thousands of times of magnification. electron microscope.

One of the leaves was quickly placed under the microscope, and when magnified 100 times, the tiny groove could be seen more clearly.

"You all come and take a look."

Wang Tiantian was the first to see the situation of the ditch, and he basically knew it, and asked other people to also take a look at the enlarged ditch.

"It's really more regular."

"See if the bottom of the groove is not, there is a little arc, which is similar to the rounding of the broach blade."

"It is basically certain that this small groove should be caused by a broach."

"."

These engineers expressed their opinions one by one, with a look of sudden realization.

Everyone has seen the situation after the enlargement of the pulling groove, so everyone returned to the blade workshop and came to the side of this horizontal broaching machine.

There have been at least a dozen people beside this broaching machine, including the head of the tooling design department, senior engineer Pan Guohua, and others.

They didn't go to the metallographic analysis room with them just now, and they didn't look at the situation after the magnification of the groove.

"Mr. Wang, how's the situation?" the head of the tooling design department asked.

Wang Tianfang said, "The situation is relatively clear. The grooves are very regular. It should be caused by the broaching process."

The section chief was silent for a while, which was the last thing he wanted to see, because the broach was designed by their people.

Pan Guohua was obviously still unconvinced, and argued, "If it was really broached by a broach, why did only a dozen or so of the more than 30 blades that have been processed have such a problem, and the other twenty or so blades have no such problem? .”

right!

The rest of the blades are perfectly acceptable without any defects.

This is not normal. If it is really caused by broaching, then every blade will be like this.

Lin Feng didn't know why this happened, and the system didn't mention the reason.

Seeing many people looking at him, Lin Feng said, "Although I don't know why there are more than [-] blades that are qualified and more than a dozen blades have grooves, but one thing is certain, the grooves of these dozen blades are broaches. caused by problems."

Pan Guohua was obviously still dissatisfied, and said loudly, "Young man, you are right, I think your deduction is not correct."

Being targeted again, Lin Feng also became angry, "It is very simple to verify whether my inference is correct, that is to repeat the accident."

What is "accident recurrence"?

This is a common method for quality accident analysis. When there is a certain inference about the cause of the quality problem, but you are not sure, you can simulate the situation of the quality accident and do it again.

Zheng Xuewen was the first to agree, "I agree to the recurrence of the accident."

Wang Tianfang also nodded, "Then let's repeat the accident, everything is ready-made, and it's easy to operate."

The director of the blade workshop specially called an experienced puller. As for the operator who was out of tolerance in batches, he had already stood aside and would not use him again until the reason was clarified.

The master craftsman moved the whole set of broaches into two boxes, and then put the blade test piece on the broaching machine.

Of course, the test piece is used, and it is still a test piece of No. 45 steel, not a high-temperature alloy, because such a test piece is low in cost, cheap, and can well verify the occurrence of quality problems.

The broaching of the first stroke is completed, and then another test piece is changed, and another broaching is performed.

A total of three specimens were broached, and then the broach was changed to the broach of the second stroke, and the broaching of the second stroke was started.

The broaching of the three test pieces was completed, and these three test pieces were immediately in the hands of Wang Tianfang, Zheng Xuewen and others. They held a magnifying glass and looked at the light carefully.

After they read it, the three test pieces began to be passed on in everyone's hands, and almost everyone looked at the condition of the test pieces.

"Comrades, what are your thoughts?" Wang Tian said loudly.

Someone replied, "Three test pieces, in the same position, have the same slight groove. I think Director Lin's deduction is correct."

At this time, Pan Guohua stopped talking.

Lin Feng said, "Whether my deduction is correct or not needs to be verified again. The No. [-] broach will be sharpened immediately, and then a few more test pieces will be drawn."

The tool and mold branch factory is responsible for the manufacture of broaches. When such a big event happened, their factory manager came early, and brought an experienced and skilled tool grinder.

The problematic No. [-] broach does not need to be sent back to the tool and mold branch factory, but is repaired at the production site of the blade workshop.

After the broach was repaired and sharpened, the knife box was installed again, and three test pieces were drawn again, and the effect was immediate.

These three test pieces are completely qualified. The tenons of the broached blades are very standard, there is no slight groove at all, the surface finish is completely qualified, and there is no slight defect in appearance.

The situation is very obvious!

It is the problem of the number seven broach!
Lin Feng's inference was very correct! ! !

Wang Tianfang put down the test piece in his hand, and said loudly, "Comrades, the root of the problem has finally been found. Xiao Lin's deduction is completely correct, and it is the problem of the No. [-] broach."

As soon as he finished speaking, he didn't know who was the first to applaud. Then, the loud applause broke out and spread throughout the manufacturing site of the blade workshop, because the workers who were working all looked sideways.

"What's wrong, they suddenly applauded."

"Looking at the happy faces of the leaders, it is likely that the problem has been solved."

"Excellent, the problem was solved in half a day."

The workers not only looked sideways, but also started discussing one by one, and some even started to ask how the problem was solved.

The applause gradually died down.

Wang Tianfang said with a serious face, "The tooling design department should conduct a self-examination to see if it is a problem with the design of the broach."

In fact, everyone knows that most of the problems are caused by the design of the broach. It's just that Mr. Wang saved some face for the tooling design department and didn't point it out on the spot.

The problem is solved!
The cause of the problem was also found!
The broaching machine started to work again, broaching the remaining turbine blades of the vortex shaft eight. Everyone did not leave in a hurry. Seeing that several blades had been processed, and seeing that there was indeed no problem at all, they dispersed one after another. go.

Wang Tianfang, Zheng Xuewen and others also left the leaf workshop in peace, but if someone is careful, they can see Wang Tianfang sighing and shaking his head several times.

Zheng Xuewen walked side by side with Wang Tianfang, he finally found out, and couldn't help asking with concern, "Boss Wang, the problem has been solved, why are you still sighing and shaking your head?"

Lin Feng, Jiang Haitao and others followed behind, and of course heard Zheng Xuewen's words.

Curious, Lin Feng thought to himself, yes, the problem has been solved, why is Mr. Wang sighing and shaking his head instead?

(End of this chapter)