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1、前言当不在纯氨气氛而是在添有含碳气体的气氛中氮化时,所形成化合物层的脆性较低,在冲击负荷下剥落倾向较小。一种说明此效果的理论认为,这是由于碳氮化合物比无碳氮化物的脆性低。另外,含碳的化合物层还具有较高的耐磨性。对于化合物层因增碳而提高韧性的进一步论证认为:在Fe-N-C三元系中,由于碳的加入,ε-相区得到扩大,以致较少的氮量也会形成ε-氮化层(Fe_2-3N),因此得到的化合物层不是ε和γ′(Fe_4 N)混合相,而是ε-氮化物单相。此理论说明:氮化层性能得以改善的根本原因不在于碳氮化合物的形
1. INTRODUCTION When nitriding is not carried out in a pure ammonia atmosphere but in an atmosphere filled with a carbonaceous gas, the compound layer formed has a low brittleness and a small tendency to peel under impact load. A theory that illustrates this effect suggests that this is due to the low brittleness of carbonitrides over carbon-free nitrides. In addition, the carbon-containing compound layer also has higher wear resistance. A further demonstration of the increased toughness of the compound layer due to carbon addition suggests that in the Fe-NC ternary system, the ε-phase region is enlarged due to the addition of carbon so that less nitrogen also forms the ε-nitride layer Fe 2 -3N), the resulting compound layer is not a ε and γ ’(Fe 4 N) mixed phase but an ε-nitride single phase. This theory shows that the fundamental reason for improving the performance of the nitride layer does not lie in the shape of the carbonitride