Yu Yueyun looked at the hourglass and calculated the time. From time to time, lift the steel column and wait for a while, and then continue quenching – this is to prevent cracks from appearing if the quenching is too hard. At the same time, it also allows people to test the aura content in the water. It is used for quenching, but it is a spiritual spring, not ordinary water.

After repeated tests, it was found that direct quenching would cause the dark iron to form a kind of 'aura insulator', but if it was quenched with a spiritual spring, this condition could be eliminated.

However, quenching is also a technical activity, the higher the quenching temperature, the harder the steel, but the higher the temperature, the easier it is to cause breakage, etc.

And how to grasp the 'degree' requires experience and a serious spirit of study.

At this point, Yu Yueyun showed a talent that shocked Zhang Haodu. They also learned from folk blacksmiths and ordinary alchemists, and studied diligently.

In just a few days, he mastered the basic requirements. Maybe not perfect, but at least it's enough to cope with the steel columns at the moment.

These steel columns, Zhang Hao does not require to reach the strength of the "high-grade magic weapon", as long as it can reach the strength of the ordinary magic weapon, it is enough. Technology should be accumulated slowly.

Half a day later, when the steel pillar had cooled down, Yu Yueyun placed the steel pillar inside another barrier, adjusted the flame temperature to 500 degrees, and heated it gently. And instructed the craftsman next to him to wait for two hours to take out the steel column and cool it naturally after placing it.

In the past two days, Yu Yueyun was busy with his feet and personally supervised the production of each steel column. Just in case, Yu Yueyun produced a total of 14 steel columns.

In the end, Zhangjiaxuan's iron output couldn't keep up, and it was even directly mobilized from the Chaocishan factory. Fortunately, the road from Chaoci Mountain to Zhangjia has been rammed, otherwise it will be another trouble.

The fourteen steel columns, each about 8.6 meters high, were expected to be eight meters high, but were increased by 0.6 meters due to the barbs reserved for lifting above.

There is a diameter of one meter and a height of eight meters below the steel column, and the upper barb has a diameter of more than 30 centimeters, forming a barb with a height of about 0.6 meters.

The weight of each steel column is around 51 tons, and the weight does not exceed 0.2 tons.

Early in the morning of the sixth day, Zhou Jue took the people of the Refining Guild with him, and he was accompanied by a few powerful masters wearing the costumes of the Jiuyang Sect.

Behind these 'middle-aged', there is also a couple of men and women who are quite arrogant, who seem to be husband and wife. The woman was talking to Zhou Xueyao, and the two women chuckled constantly.

Next to her, Mu Yingying looked at Zhou Xueyao vigilantly, her eyes swaying between Zhang Hao and Zhou Xueyao from time to time.

Zhou Jue came over, "Brother Shi, let me introduce you to you." This is the hall master of the Jiuyang Sect Refining Hall, Zhang Xinhan's uncle, and the early stage of the Yuan Infant. The means of refining weapons are unmatched. ”

Zhang Xinhan nodded to Zhang Hao with a cold face, and said coolly: "Don't listen to his nonsense." In terms of refining, I can only say that there is no one in my generation who can match it. Compared with some elders, elders, etc., there are still shortcomings. ”

Zhang Hao: ...... Are you humble or boastful?

Zhou Jue's face was also a little embarrassed, and he didn't have the desire to go into detail, so he casually pointed to Zhang Xinhan behind him and said simply: "These are all from the Jiuyang Sect Refining Hall." ”

Then he pointed to the pair behind him: "These two are from Xinglintang, Uncle Lu Yang, and Xiao Xiao, Lu Yang's wife, are both in the infancy stage."

Senior Uncle Lu Yang is the best refiner in Xinglin Hall, especially in refining the Dan furnace. Uncle Xiao Xiao is unique in alchemy. Many of the pills that were refined for you before were refined by Uncle Zhang. ”

As he was talking, someone from the Xuantie Factory also came, and Li Yousheng and Li Yuanyuan, who led the team, were dressed fresh and beautiful. However, Li Yuanyuan saw Zhou Xueyao for the first time.

I don't know if beautiful girls are born with the attribute of mutual attraction.

Today's Zhou Xueyao did not wear a veil, she was plain and facing the sky, but she was extraordinary, and I don't know how many people's eyes were attracted.

It just so happened that Zhou Jue introduced Lu Yang and Xiao Xiao, and Zhang Hao and Zhou Xueyao talked and laughed. Seeing that the two were very familiar, the shyness on Li Yuanyuan's face instantly faded.

An inexplicable sense of crisis, a little sourness, rose in her heart. The woman who suddenly appeared looked ...... It's excellent.

Zhang Hao and Zhou Xueyao spoke, and said to everyone: "Thank you for coming to Zhang's house in your busy schedule. Don't say polite words, the Zhang family has prepared the embryo of the Dutian Fire Array, please come with me. ”

The 14 8.6-meter-high steel pillars standing in the Zhang family's compound are too obvious for everyone to see outside. However, I didn't know what it was at that time: the surface of the steel column that was quenched and tempered in the ground fire environment was pitch black, and the Zhang family did not polish it, so there was really no brilliance of 'dark iron'.

Zhou Jue stood under the steel pillar, looking up at the steel pillar, the shock in his heart was indescribable.

One meter in diameter, two people need to hug each other. And at 8.6 meters in height, there are almost five people in height.

These steel columns, which weighed more than 50 tons, were just placed on the ground, and after only one night, the ground was pressed down to a depth of one foot.

Gently stroking and silently feeling these heavy 'iron pillars', the shock in Zhou Jue's heart became more and more intense. These iron pillars are made of 96% pure black iron, and the structure is dense and completely cast at one time.

Carefully pressed with his fingernails, but did not move, only rubbing off a little black skin, revealing the blue and scorching steel inside.

Zhou Jue was even more surprised. As a master of the middle Yuan Infant period, his nails are hard enough to cut gold and jade, and ordinary, unforged dark iron is enough to leave deep cuts.

Unconvinced, Zhou Jue turned the true yuan, the cold light on his nails flashed, and he grabbed the steel pillar again.

But the next moment, Zhou Jue's face was distorted. Fingernail...... Bent!

It hurts!

Covering his claws, Zhou Jue turned his head cautiously to see if anyone saw his ugly appearance, and he didn't want everyone to be stunned by the steel pillar in front of him, no one would care.

The refining hall of the Jiuyang Sect advocated Xin Han and was hammering with his fist, but the steel pillar of more than fifty tons did not move at all, and there was not even a sound.

After hammering for a while, he only hammered off part of the black skin, revealing the steel that glowed with blue light inside.

Zhang Xinhan retreated a few steps, looked at the height of the steel column, turned his head and asked Zhang Hao: "Do you really want to engrave the Dutian Fire Array on this?"

"Yes. I troubled the seniors. ”

Zhang Xinhan nodded coolly, took out a sharp chisel with treasure light flowing, and chiseled it at the bottom of the steel column.

There was a sonorous bang, sparks, and a sharp chiseled tip...... Broken!

Broken!

Zhang Xinhan looked at the chisel in his hand, and then looked at the steel pillar that only left a little mark, with an embarrassed expression.

Zhang Hao waited for a while, but didn't see Zhang Xinhan speak or move, so he had to speak carefully: "Senior?"

"Ah......" Zhang Xinhan woke up and stood up, unable to maintain his cool expression anymore, "You guys...... Why is the dark iron so hard, my high-grade magic weapon quality chisel has collapsed!"

"The quality of the top-grade magic weapon?" Zhang Hao was a little puzzled, "Our pillar has only reached the quality of the medium-grade magic weapon!"

Yes, Zhang Hao is sure that it has only reached the quality of a medium-grade magic weapon. Originally, Zhang Hao asked that as long as he reached the quality of low-level magic weapons, it would be good. But Yu Yueyun insisted on refining the quality of a medium-grade magic weapon.

Zhang Xinhan was stunned for a moment, and suddenly asked, "How do you define quality?"