Seeing Li Xiang's expression, Dong Huai took out several other turning tools from the box, and said: "Lord Li, please see, this is a cutting knife, and the other is an inner hole knife, we have also conducted detailed tests on these two kinds of knives, and the results are not bad, but the cutting edge of the cutting knife is easier to wear, so not only should we strictly select materials during production, but also find ways to improve the yield rate." Pen ~ fun ~ Ge www.biquge.info as for the inner circle cutter, it is not easy to grasp its position when fixed, and it is easy to cause some errors, but we have improved the fixture, which can be regarded as solving some problems. ”

Li Xiang didn't know what to say at this time, but said repeatedly: "Okay! Good! Good! He obviously didn't expect Dong Huai to be able to make so many kinds of knives. In fact, the metallurgical industry in the Song Dynasty was extremely advanced, and the iron carving technology at that time had been able to carve a wrought iron ingot into various shapes, and the knives used in the carving were also made according to this method, but Dong Huai got Li Xiang's booklet, and studied with the iron factory for several days, and made a number of improvements to the smelting process, and at the same time adopted more advanced technology in the quenching and tempering treatment, so the knives made this time are naturally more suitable for continuous cutting than ordinary carving knives.

After a while, Li Xiang finally came back to his senses, and suddenly remembered something again, and said: "Lord Dong has really been busy in the past few months, and he has been able to make so many kinds of knives, but this kind of knives does not need to be made in large quantities, as long as dozens of them are made every day." ”

Dong Huai was stunned when he heard this, the smile on his face suddenly disappeared, and he said with a sad face: "Lord Li, with the current conditions, it is still difficult to make dozens of turning tools every day, because the grinding of knives is extremely complex, and the installation surface of the knives must have a certain flatness, so it is good to make more than ten knives a day." ”

Li Xiang said with a smile: "Master Dong doesn't need to be in a hurry, it will naturally be easy when you have a new production tool." By the way, how about this tool for cutting copper alloys? ”

Dong Huai said: "If it is used to cut ordinary copper, it is not too difficult, but there are some problems when it comes to cutting the bronze alloy used for casting swords. Xia Guan had tried it with Master Hu, and the hardness of this knife was only slightly higher than that of a copper sword. ”

Li Xiang knew that the hardness of copper-tin alloy was much higher than that of ordinary wrought iron, so he was not too surprised to hear Dong Huai's words, which was also determined by the current tool material. In fact, turning tools are usually made of high steel or alloy steel, in the current situation, high steel tools obviously cannot be manufactured, and alloy steel tools have become unlikely because the metallurgical industry has not developed. Li Xiang is aware of this, so he does not have too many requirements for tools, as long as he can cut common cooked parts and copper, it can be regarded as meeting the requirements.

Dong Huai took out another cylindrical piece of iron and said, "My lord, in fact, the biggest gain of Xia Guan in the past few months is not to make knives, but to make this piece of cast iron. Later, Hu Daren mixed dolomite in iron ore and smelted it together, and then refined the obtained material and coke repeatedly, and then referred to some methods left over from the Han Dynasty, and obtained this kind of cast iron. ”

Li Xiangqi said: "What is so special about this kind of cast iron? ”

Dong Huai said: "This kind of cast iron has excellent malleability, and it is particularly wear-resistant, and what is even more peculiar is that its strength is not much worse than that of stainless steel, and the hardness is better than that of pig iron." Speaking of this, Dong Huai couldn't hide his excitement in his heart, and his voice trembled a little.

Li Xiang was taken aback when he heard this, and hurriedly said, "Master Dong, you say it again, what have you added?" Dong Huai saw Li Xiang's expression like this, and knew that the matter was very important, so he described what he just said in more detail. Li Xiang frowned and thought about it for a long time, but he still couldn't think of a reason, because according to what Dong Huai just described, this kind of cast iron is the characteristics of ductile malleable cast iron, but this kind of cast iron only appeared in the eighteenth century, how could the craftsmanship of the Song Dynasty make pearlescent ductile iron?

Li Xiang couldn't guess the reason for a while, thinking that maybe it was because some additives were added, which happened to be able to refine rare earth metals, which provided more crystal nuclei, so that graphite could just exist in cast iron in a spherical shape, or maybe this was not ductile iron at all? But in any case, since this kind of cast iron has such properties, it will be used well in the future.

In fact, some iron tools have also been unearthed in the iron-smelting sites of the Western Han Dynasty, and later generations of scientists have been tested by modern metallographic technology, and now they contain radial spherical graphite, and the nodularity is equivalent to the modern standard level. Historically, the silicon content of cast iron in ancient China was low for a long period of time, that is to say, in the Western Han Dynasty, the spherical graphite in Chinese iron has been obtained by softening and annealing of low-silicon pig iron castings.

Li Xiang naturally also knows that ductile iron is widely used, such as crankshafts on the motor, automobile chassis parts, diesel bodies, various gears, high-pressure iron pipes, etc.

Dong Huai saw Li Xiang there bowing his head and pondering, and he didn't know what he was thinking for a while, so he waited quietly on the side.

After a while, I heard Li Xiang say: "Master Dong, since the turning tool can be manufactured, I don't know what happened to the other lathe parts?" ”

Dong Huai hurriedly said: "The batch of lathe parts painted by adults, a small part of the casting has been completed, the base and guide rail are made of copper, of course, in order to prevent thermal deformation, we have made dimensional corrections at room temperature after casting, and the axle is made of new cast iron just mentioned, in order to improve the lubrication of the shaft and bearing, the bearing is made of some copper materials, but ......"

Li Xiang hurriedly asked, "Just what?" ”

Dong Huai said: "It's just that most of these parts are casting, naturally there are some errors in the size, and Li Daren's requirements for its strength and hardness are quite high, so it is inevitable that there are some matching clearances, such as the matching of bearings and shafts, the coordination of gears and racks, there are some clearances, but there is no such problem as the feeding mechanism, the craftsmen first used the scraper to correct, and then adopted the method of grinding, and can easily go back and forth to advance and retreat the knife holder. As for the lead screw and heel tool holder, a suitable manufacturing method has still not been found. ”

Li Xiang nodded, thought for a while, and said: "It's no wonder, judging from the current casting methods, it will definitely be difficult to achieve such high precision requirements, but as long as these mechanisms can be moved, it is not bad." As for more precise lathe parts, a manufacturing method will be found as soon as possible, and the tool passing device was originally intended to be used in conjunction with the screw rod, since the screw has not been made, there is no way to debug the tool passing device for the time being. By the way, can you make the kind of drill bit I mentioned last time? (To be continued.) )