摘要:
A method for sintering Mn--Zn ferrite green compacts is provided which includes a first heating step of raising the temperature from room temperature to 600.degree. C. within a period from 30 minutes to 5 hours, a second heating step of raising the temperature from 600.degree. C. to the sintering temperature and holding the sintering temperature until the start of cooling within a period shorter than 10 hours, and a cooling step of lowering the temperature to 150.degree. C. within a period longer than 3 hours, with the total period of the three steps being shorter than 20 hours. This method permits the efficient production in a short time of Mn--Zn ferrites having good magnetic properties.
摘要:
The improved version of a chromated metal sheet has a chromate layer on at least one side of a metal substrate or a plated metal substrate and it is characterized in that the chromate layer has a chromium deposit of 10-200 mg/m.sup.2 per surface in terms of metallic Cr, that the chromate layer contains silica in an amount of 0.1-6.0 in terms of the weight ratio of SiO.sub.2 to Cr, and that the chromate layer contains at least one kind of lubricating particles selected from the group consisting of graphite, MoS.sub.2, BN, calcium stearate and an organic lubricating substance in an amount of 0.1-100 in terms of the weight ratio of the lubricating particles to Cr. The lubricating particles can have a surface layer capable of nonionic surface activating action, and this surface layer accounts for 1-70 wt % of the lubricating particles. The chromated metal sheet has sufficient lubricity to withstand press forming in the absence of lube oil coatings, has high enough electric conductivity to present no problems in spot weldability and groundability, and has sufficiently high corrosion resistance to withstand use in a naked state.
摘要翻译:铬酸盐金属片的改进版本在金属基材或电镀金属基材的至少一侧上具有铬酸盐层,其特征在于铬酸盐层具有每表面10-200mg / m 2的铬沉积物 的铬酸盐层,所述铬酸盐层以SiO 2与Cr的重量比计含有0.1-6.0的二氧化硅,并且所述铬酸盐层含有选自石墨,MoS 2中的至少一种润滑颗粒 ,BN,硬脂酸钙和有机润滑物质,其量为0.1-100,以润滑颗粒与Cr的重量比计。 润滑颗粒可以具有能够非离子表面活化作用的表面层,该表面层占润滑颗粒的1-70重量%。 铬酸盐金属片具有足够的润滑性以在不存在润滑油涂层的情况下经受压制成形,具有足够高的导电性,不存在点焊性和可研磨性方面的问题,并且具有足够高的耐腐蚀性以经受在裸露状态下的使用。